A US drone strike on Thursday killed eight militants in a Taliban stronghold of Pakistan's tribal belt, bringing the death toll from such strikes to 12 in two days, Pakistani officials said.
"The drone fired two missiles on a house in Hassokhel town," 25 kilometres (16 miles) east of Miranshah, the main town in North Waziristan, a security official said.
"At least eight militants have died," a senior military official said in Peshawar, the main city in the northwestern Khyber Pakhtunkhwa province.
Two other officials confirmed that the death toll had risen from five to eight.
Washington considers Pakistan's semi-autonomous northwestern tribal belt on the Afghan border the main hub of Taliban and Al-Qaeda militants plotting attacks on the West and in Afghanistan.
North Waziristan is a stronghold of the Haqqani network -- Afghan insurgents blamed for a series of spectacular attacks on Western targets in Kabul -- and Taliban.
Islamabad has resisted US pressure to launch a sweeping offensive in the area, arguing that it is too overstretched fighting homegrown insurgents elsewhere to take on entrenched groups whose primary focus is US troops in Afghanistan.
Residents and local officials said the strike damaged a nearby mosque where three worshippers believed to be Central Asians were fatally wounded. "They were seriously wounded and died later in the hospital," a security official said.
A neighbour, Mohammad Rafiq, told AFP the attack triggered a fire at the compound of the house where militants were exercising in the courtyard.
It was the fourth US drone strike reported in Pakistan since parliament in March demanded an end to the strikes, and the second in as many days.
Pakistani-US relations went into free fall last year, starting when a CIA contractor shot dead two Pakistanis, then over the American raid that killed bin Laden on May 2 and lastly over US air strikes that killed 24 Pakistani soldiers in November.
After the air strikes, Pakistan shut its Afghan border to NATO supplies and ordered US staff out of an air base reportedly used as a hub for drones.
In March, parliament agreed to reset US relations but on condition that Washington apologise for the soldiers' deaths and end drone attacks on its soil.
Islamabad, which is understood to have given its tacit approval for the attacks on Al-Qaeda and Taliban targets in the past, has become increasingly vocal about its opposition to the perceived violation of national sovereignty.
But US officials believe the drone attacks are a valuable weapon in the war against Al-Qaeda and other Islamist militants.
At a NATO summit this week, Barack Obama appeared to snub Pakistani President Asif Ali Zardari over Islamabad's refusal to lift a six-month blockade on NATO transit rights into Afghanistan.
According to an AFP tally, 45 US missile strikes were reported in Pakistan's tribal belt in 2009, the year Obama took office, 101 in 2010 and 64 in 2011.
The New America Foundation think-tank in Washington says drone strikes have killed between 1,715 and 2,680 people in Pakistan in the past eight years.