Huge explosions at a munitions depot in Brazzaville killed 146 people and injured hundreds more while flattening buildings, homes and a Catholic church in the Congo's capital city.
An emergency cabinet meeting early Monday issued a plea to international organisations to help the victims while Congolese President Denis Sassou Nguesso announced a curfew in the city and set up an exclusion zone around the .
The government said that an electrical circuit fault likely caused a fire which triggered a series of blasts so powerful they devastated the surrounding area and broke windows in Kinshasa, the capital of the neighbouring Democratic Republic of Congo several miles (kilometres) away.
The toll "stands at 146 at the moment, along with considerable damage," according to a statement released after the cabinet meeting.
Local residents told AFP they thought the number of deaths was higher.
The Catholic church, close to the barracks, collapsed when the explosions occurred during Sunday morning mass.
A French diplomat in the capital speaking to AFP by telephone also put the toll higher.
"We count at least 150 dead in the military hospitals and around 1,500 injured, some of them seriously," he said.
Interior Minister Raymond Mboulou told AFP the area around the munitions depot in the eastern district of Mpila had been devastated with "many houses burned to the ground".
"I experienced the apocalypse," said Jeanette Nuongui, 36, the sole survivor from a family home that was destroyed in one of the explosions.
"It is by the grace of God I am here. My mother died, my father, my two brothers and my two sisters also. There's nothing left."
Among the victims were at least six Chinese workers employed by the Beijing Construction Engineering Group, according to China's Xinhua news agency.
A number of houses were completely destroyed, while others had windows and doors blown out and roofs lifted, an AFP correspondent said.
A woman living in the capital described the chaos and panic in the immediate aftermath of the blasts.
"There are many people on the street. They are running away, barefoot, carrying parcels on their heads. Some are hardly dressed. There are no cars, no buses, no taxis," she said.
"The search for survivors remains a priority," the cabinet statement said, adding that an evaluation team was attempting to assess the damage and come up with ways to deal with the disaster.
"In the light of events, and pending the findings of an enquiry, a short circuit seems to have caused a fire which spread through the central depot of arms and munitions, causing the deaths of some 100 of our compatriots," the statement said.
The main fire had been brought under control by the early hours of Monday.
The country's health minister Georges Moyen told the cabinet meeting that extra medical personnel were being made available "to offer the best care in this tragic situation."
The cabinet also sent out a call to "several international organisations" for help and support, the statement added.
The grounds of Brazzaville cathedral and a local covered market were turned into makeshift emergency housing centres.
At least five strong explosions rocked the Mpila military barracks in the east of the capital between 8:00 am (0700 GMT) and 10:45 am Sunday after a blaze in two munitions depots.
A series of weaker detonations continued into the late morning, hampering firefighters and rescue workers.
River traffic between Kinshasa and Brazzaville was also suspended, a Kinshasa port official said.
French Foreign Minister Alain Juppe said he had ordered his office to send emergency aid "which will arrive soon in Brazzaville."