10:10 GMT - AFP IS CLOSING THIS LIVE REPORT as Malaysia says two objects spotted by a satellite in the Indian Ocean were a "credible lead" in the search for the missing passenger jet.
"We now have a credible lead," Transport Minister Hishammuddin Hussein told reporters at Kuala Lumpur International Airport.
This "requires us overnight to verify and corroborate it," Hishammuddin said, adding that the overall search and rescue effort for Flight 370 would continue in the meantime.
Earlier Australian Prime Minister Tony Abbott told parliament that "new and credible information" based on satellite imagery had come to light, and four long-range surveillance planes were being diverted to look into the find in the southern Indian Ocean.
The Australian Maritime Safety Authority had said that the vast area it was scouring had been "significantly refined" following closer analysis of flight MH370's fuel reserves.
The largest object sighted in the search is 24 metres (79 feet), with a second, smaller object also spotted, Australian authorities said Thursday.
10:03 GMT - Much to do - "For families around the world, the one piece of information they want most is the information we just don’t have: the location of MH370.
"Our primary focus has always been to find the aircraft. And with every passing day, our efforts have intensified.
"Yesterday I said that we wanted to reduce the area of the search. We now have a credible lead. There remains much work to be done to deploy the assets. This work will continue overnight," Hishammuddin said in conclusion.
10:02 GMT - Search continues - "Until we are certain that we have located MH370, search and rescue operations will continue in both corridors. I can confirm that Malaysia is sending 2 aircraft to Kazakhstan, and the UK is planning to send 1 ship to the southern corridor."
09:59 GMT - Information - Asked if there had been any reluctance from Australia and the US to hand over satellite data, the minister said:
"I can confirm we have had no reluctance from any our partners in this search and rescue operation."
09:56 GMT - Counterparts - Hishammuddin said that during the course of the operation, the Chief of the Defence Force had spoken to his counterparts from several countries including: Australia, China, India, Indonesia, Japan, Maldives, Nepal, New Zealand, Singapore, Thailand, Vietnam, The UK, and the USA.
"All were very supportive, and all offered their assistance," he said in his statement.
09:55 GMT - Asked if any help would be given to Chinese families to go to Australia, Ahmad Jauhari Yahya said: "Assuming it is confirmed that the aircraft is found close to Australia, we will obviously make arrangements for them to fly there."
09:53 GMT - Updates - Frequent updates were given to family members now in Kuala Lumpur, Malaysia Airlines chief executive Ahmad Jauhari Yahya said. He said officials are investigating why family members had come to the media centre yesterday and the reasons for it.
09:49 GMT - More planes - Hishammuddin said the Australian Maritime Safety Authority (AMSA)continues co-ordinating the search and its Rescue Co-ordination Centre (RCC) had tasked another 3 aircraft to the area, including a second Royal Australian Air Force (RAAF) Orion, a Royal New Zealand Air Force Orion, and a US Navy P-8 Poseidon.
An RAAF P-3 Orion aircraft had arrived earlier.
The Poseidon was expected to arrive early this afternoon. The second RAAF Orion was expected to depart RAAF Base Pearce, Perth, mid-afternoon. The New Zealand Orion was due to depart this afternoon.
09:44 GMT - Importance - Asked how important the latest lead was, Hishammuddin says "All leads are at the same level of importance. Any lead has to be corroborated and verified. If false not only will it jeopardise investigation but it will also give false hope to family members."
09:40 GMT - Credible - Asked "How do we go forward if there is no evidence?"
Hishammuddin replied: "Today what I am comfortable with saying is that at least there is a credible lead." It has to be verified and corroborated, he said.
09:39 GMT - Beijing meet - "China ready to send ships and aircraft wherever they are needed," Hishamuddin says, adding high-level team from Malaysia is leaving to meet family members in Beijing this evening.
09:35 GMT - Hishammuddin goes on to list the assets deployed as 18 ships, 29 aircraft and six ship-bound aircraft deployed in North and South corridors.
"I am thankful for the cooperation of our partners"
09:35 GMT - "It must be stressed these sightings, while credible, must still be confirmed."
09:33 GMT - Hishamuddin says the "images were captured by satellite they may not be that of the aircraft.
09:33 GMT - Press conference - Press conference with Malaysian officials opens.
Present are Transport Minister Hishammuddin Hussein, Foreign Minister Anifah Aman, civil aviation chief Azharuddin Abdul Rahman and Malaysia Airlines CEO Ahmad Jauhari Yahya
09:13 GMT - Eagerly waiting - Malaysian air force chief General Rodzali Daud says Malaysia's Air Force has not sent any assets to the area in the Indian Ocean where the floating objects were spotted.
"It's too far for us. It's all done by Australia," he tells AFP.
Asked if he had received any confirmation the objects had been found or that they were indeed from the missing plane, he said he had not received any information as yet. "I'm waiting as eagerly as you."
08:59 GMT - "Briefed" - Rod Smith, Australian High Commissioner to Malaysia, tells reporters after leaving a meeting with Malaysian officials at a hotel at Kuala Lumpur International Airport: "I have briefed the minister (Hishammuddin Hussein), and the minister will be at the press conference shortly."
08:44 GMT - A Malaysian government press conference on the situation is expected around 09:30GMT
08:23 GMT - "Not good news" - Tony Fernandes, the boss of Malaysia Airlines rival AirAsia, has tweeted:
"On my way home. It's not good news but here's hoping that MH370 is found. #PrayForMH370.
"Have to say that the press briefing by Australia was clear. I really hope that this time it leads to something conclusive." AirAsia is Asia's largest budget carrier by capacity.
08:20 GMT - Beijing's foreign ministry spokesman Hong Lei said in a statement China is paying "great attention" to the news.
"The Chinese side is ready to make relevant arrangements based on the latest updates," he added, without elaborating.
08:18 GMT - Arrive - A merchant ship was expected to arrive in the vicinity around 0700 GMT. No news yet
07:24 GMT - Reality - Anthony Brickhouse, associate professor of aerospace and occupational safety at Embry-Riddle Aeronautical University in the United States, told AFP:
"Every investigator, you kind of have to be middle of the road. You're not a pessimist, you're not an optimist, you're basically what I like to call a realist. And it sounds like right now that this is good information but until they definitively figure out that this is from flight MH370 you really don't get too excited, you have to temper your emotions so to speak.
"If you remember about a week ago the Chinese put out information that they have picked up information that they have picked up something on satellite and everybody got really excited about it and it turned out to be nothing.
"This seems a little more credible than what the Chinese found but until they can actually get down there and identify the wreckage as being part of MH370 we really don't know yet."
07:18 GMT - AFP reporter Bhavan Jaipragas spoke to two analysts:
David Kaminski-Morrow, air transport editor, Flight International:
"After several false starts, it's natural that any new information will be treated with extreme caution. Similar-sized objects reported by Chinese satellites were eventually dismissed as unrelated.
"It's the best lead simply because, with so little information, it's effectively the only lead. The key issue initially will be ensuring that the items seen can be located by search teams capable of making a closer examination.
"While a timeframe is hard to estimate, the inquiry needs to conduct its assessment as quickly as possible because the ocean is constantly shifting and, should the debris be significant, every hour of drift adds uncertainty to position data."
Andrew Herdman, director-general, Association of Asia Pacific Airlines:
"I think it is quite significant that they decided to release the information through a statement from Prime Minister Abbott, they obviously think it is important and credible. But both the prime minister and Dr John Young exercised great caution not wanting the public to draw too much from the information. John Young has significant experience in search and rescue, and if he is cautious, I think we have to be as well
"They keep talking about images from satellite but John Young used the word 'blob', meaning the image may not be high resolution. The length of 24 metres seems too precise for me in such a case and I think it is premature to say whether is from any part of the aircraft.
This development raises hopes that we are coming closer to some kind of closure but we need to maintain a sense of perspective and reality. The task is getting much harder."
07:07 GMT - Little more is likely to be known until the four aircraft that have been dispatched, including a Royal Australian Air Force Orion and a United States Navy P8 Poseidon, arrive at what Australian Defence Minister David Johnston described as "a most isolated part of the world".
The AP-3C Orion is an extremely versatile aircraft used to conduct long-range surveillance missions throughout the Indian and Pacific oceans.
The Orions are fitted with radar, infra-red and visual systems which allow crew to see objects at night and in the distance, as well as magnetic anomaly detectors which help in identifying metal.
The Poseidon is an even more advanced aircraft described by the US as a long-range anti-submarine warfare, intelligence, surveillance and reconnaissance plane aircraft capable of broad-area maritime operations.
06:45 GMT - MP tweet - A tweet from Malaysia PM, with poignant hashtag:
Mohd Najib Tun Razak @NajibRazak
Meeting my Chief of Defence Force. After call from @TonyAbbottMHR, awaiting confirmation from Australia on the objects found. #PrayForMH370
Key questions remain
06:41 GMT - Cellphones - Another question is why none of the passengers tried to contact relatives, as they did during the 9/11 attacks.
Experts say the chances of those on board being able to use their mobile devices would have been better the closer they were to a mobile network on the ground, but many are sceptical they could have done so travelling at speed, particularly at cruising altitude.
Without a small cellular base station on board, which was not available on Flight 370, a cellphone cannot be used at an altitude of more than roughly 0.5 kilometres in the case of a commercial airliner, and must not be too far from a cell tower.
Even the absence of phone calls or emails could provide clues.
It may indicate that the plane was flying too high or was over water, or the passengers were unconscious, possibly due to a change in cabin pressure.
06:19 GMT - Fundamental questions - If the debris does turn out to be from the plane it is likely to raise as many questions as it answers.
Authorities still have no clear idea what happened to the flight, but suspicion has fallen increasingly on the missing plane's chief pilot, Captain Zaharie Ahmad Shah, ever since investigators concluded the plane's communication systems were likely disabled manually and the aircraft diverted by a skilled aviator.
A US official who spoke to AFP on condition of anonymity said Malaysia had asked the FBI to help recover data deleted from a flight simulator belonging to Zaharie, a 33-year veteran of the airline, who was highly regarded by his peers.
Malaysian police removed the simulator from Zaharie's home on Saturday, after investigators said they believed the plane had been deliberately diverted from its intended route by someone on board.
06:14 GMT - Disorientated - In Beijing, while some of the relatives said there was "no new information" when approached by AFP, many leaving the briefing room appear in a more sombre mood than in previous days.
Many link arms as they walked past about 70 reporters gathered outside the room, looking downwards or covering their faces amid the sound of cameras.
Others march quickly past the media crowd, appearing disorientated as they search for the exit.
"I am sick of hearing there is new information only for it to be dismissed later," one man tells AFP angrily.
06:07 GMT - For most families and relatives the wait goes on as they wonder if the news means something or may just be another bump in the rollercoaster emotional ride they have had to endure so far.
At a hotel near the Kuala Lumpur International Airport, where a dozen Chinese relatives are staying, some are having lunch at the hotel cafeteria, looking dazed and tired, sitting quietly and gazing at the cloudy skies.
Met by three officials, two women listened attentively, while an anxious-looking man kept dropping his head between his legs. Another family held hands as they finished their meal and slowly walked back to their rooms, reports AFP's Julia Zappei.
05:56 GMT - "Logistical nightmare" - However, authorities are keen to emphasise how difficult the search still is and that nothing is certain yet.
Speaking to Sky News Australia Australian Defence Minister David Johnston warns the operation is "a logistical nightmare. This is a terribly complex logistical operation to identify what we have found via the satellite.
"We are in a most isolated part of the world, in fact it probably doesn't get, if I can be so bold, more isolated.
"We are doing everything we can to try to solve this potentially tragic mystery."
05:53 GMT - Some of the relatives seem to be setting great store by the news.
"My son is still alive. My son is still alive. I don't believe the news," exclaims Wen Wancheng, 63, from Shandong province, whose son was on the flight, as he makes his way through a throng of reporters at the Lido Hotel in Beijing.
05:16 GMT - False leads - Hishammuddin says Abbott has called his Malaysian counterpart Najib Razak to discuss the latest development.
"This time I just hope that it is a positive development," Hishammuddin says and warns it may be some time before the find can be verified.
"Aircraft and vessels are going there, you know how huge the area is."
The search has been dogged by previous false leads, including Chinese satellite images of suspected debris published earlier which turned out to be a red herring.
05:06 GMT - "Verify" - Transport Minister Hishammuddin Hussein tells reporters at Kuala Lumpur International Airport, where he is overseeing the international search effort, the find still needs to be verified.
"We have been very consistent. We want to verify, we want to corroborate."
05:04 GMT - The families in Malysia seem to be sharing much the same feelings as those in Beijing, Julia Zappei tells me from Kuala Lumpur.
Selamat Umar, a 60-year-old retiree, tells AFP via telephone, "Right now it is just a possible clue. I am waiting for confirmation. I am waiting in hope." His 29-year-old son Khairul Amrison, an aviation engineer, is on the plane.
04:59 GMT - Unclear - Families waiting for updates at the Lido Hotel in Beijing appeared to be unclear about the news coming from Australia, reports Sebastien Berger.
Zhao Chunzeng told AFP they were all looking for a confirmed discovery.
"We are waiting, just waiting and we can't respond to news until it is definitely confirmed," said Zhao, a 43-year-old from Beijing, who declined to say which relative was on the plane.
Asked if he felt that the Australian announcement provides greater significance as it was the prime minister who made the statement, he said: "Maybe, but we will still have to wait and see."
04:51 GMT - The objects are located in the southern Indian Ocean about 2,500km (1,550 miles) southwest of Perth on Australia's west coast.
"Weather conditions are moderate but poor visibility has been reported, which will hamper air and satellite efforts," says Young.
04:49 GMT - Rubbish - Asked if the finds could just be rubbish in the water Young says: “There is debris out there – it can be containers from ships falling over board… But on this occasion, the size and the fact there are a number located in the same area – but I don’t want to speculate.”
04:48 GMT - Indistinct - "The objects are relatively indistinct. The indication to me is of objects that are of a reasonable size and probably awash with water and bobbing up and down over the surface."
04:43 GMT - "We want to find them and we want to find out what they are from seeing.
"On this particular occasion the size and the fact there are a number in the same area makes it really worth looking at.
"We need to locate it, recover it and bring it a long way back to Australia. What we are looking for is confirmation that it does belong to the aircraft or it does not."
04:41 GMT - "I don't want to draw too much from this. It's a lead. It's probably the best lead we have so far, but we need to get there first," says Young.
04:41 GMT - Australia officials are saying in live speech that the satellite imagery is “credible enough to divert the search to this area.”
04:39 GMT - John Young, Australian Maritime Safety Authority General Manager, tells a press conference the largest object found is about 24 metres (79)
04:31 GMT - Malaysian Subramaniam Gurusamy, 60, who lives in the Malaysian port town of Klang and whose 34-year-old son Puspanathan Gurusamy was on board, tells AFP by phone.
"I think we need to confirm first if the two objects are part of the missing plane. Are you saying the plane has gone into the sea?”
"So many people are praying for the safe return of my only son. I am praying every day for his return. But if something bad happens what can I do?"
04:25 GMT - Hope alive - My colleague Sebastien Berger reports that at the Lido Hotel in Beijing where relatives of the 153 Chinese passengers are gathered, Wen Wancheng, whose son was on the flight, told AFP: "I hope all the people on board are alive."
Asked if he firmly believed the relatives were still alive, the 63-year-old from Shandong province replied: "Yes, all alive, firmly believe."
04:18 GMT - Statement - A press statement from Minister of Defence and Acting Transport Minister Hishammuddin Hussein has been issued:
“At 10:00 this morning, Prime Minister Najib Razak received a call from Prime Minister Tony Abbott of Australia, informing him that ‘two possible objects related to the search’ for MH370 had been identified in the Southern Indian Ocean. The Australian High Commissioner has also briefed me on the situation.
“At this stage, Australian officials have yet to establish whether these objects are indeed related to the search for MH370.”
04:14 GMT - "Credible" - Quoting a source familiar with the find told The Australian newspaper reported the sightings were "credible" and consistent with "what you'd normally find in such circumstances".
But Australian officials are warning the search is like looking for a "needle in a haystack" and the chances of finding any surface wreckage are slim, with planes not equipped to look underwater.
04:09 GMT - "Praying hard" - Asked if Australia has informed Malaysian authorities of the finds, Malaysia Transport Minister Hishammuddin Hussein, has sent an SMS to AFP saying :
"Meeting their delegation: as from day one we follow up every lead. Praying hard!"
04:06 GMT - "Top priority" - Earlier US President Barack Obama designated the search for the plane a "top priority" for his government, with FBI agents working alongside Malaysian authorities to help unravel the mystery.
04:01 GMT - What? - Asked to confirm Abbott's statement, Malaysia's civil aviation director, Azharuddin Abdul Rahman, at Kuala Lumpur International Airport, says he doesn't know.
"I can't give any comment. What have they found? They have found something? We have not received anything yet from them."
03:56 GMT - Search area - The search area is enormous.
Since Tuesday Australian, US and New Zealand long-range surveillance planes have been scouring a tract of the southern Indian Ocean measuring 305,000 square kilometres (122,000 square miles), some 2,600 kilometres southeast of Perth.
03:52 GMT - Security - My colleague Julia Zappei in Kuala Lumpur tells me that authorities have tightened security at a hotel next to the Kuala Lumpur International Airport after several relatives of Chinese aboard the missing plane stormed the media conference room Wednesday, accusing authorities of withholding information and doing too little to find the plane, just before Malaysian officials started their daily briefing.
An AFP reporter says several policemen and armed military personnel are standing guard near the cordoned off room.
03:51 GMT - "southern sector" - Australia has been responsible since Monday for searching the "southern sector" of the massive operation to locate the Boeing 777, which disappeared on March 8 en route to Beijing with 239 passengers and crew on board, at the request of Kuala Lumpur.
The Malaysian government believes the jet was deliberately diverted and flew for several hours after leaving its scheduled flight path -- either north towards Central Asia, or towards the southern Indian Ocean.
03:47 GMT - The Australian Maritime Safety Authority (AMSA)is due to hold a news conference with more details at 0430 GMT
03:45 GMT - Premature conclusions - Abbott is, however, warning against drawing premature conclusions.
"We must keep in mind the task of locating these objects will be extremely difficult and it may turn out that they are not related to the search for flight MH370."
03:42 GMT - Satellite images - "The Australian Maritime Safety Authority (AMSA) has received information based on satellite information of objects possibly related to the search."
"Following specialist analysis of this satellite imagery, two possible objects related to the search have been identified."
Abbott says he has informed Malaysian Prime Minister Najib Razak.
03:35 GMT - WELCOME TO AFP'S LIVE REPORT on the search for Malaysia Airlines Flight MH370 as Australian Prime Minister Tony Abbott says two objects possibly related to the search have been sighted.
Abbott told parliament "new and credible information" had come to light nearly two weeks after the plane vanished.
He said an Australian air force Orion had been diverted to look into the objects. He did not specify where they were but Australia has taken charge of the search in the southern Indian Ocean.