A pre-dawn US missile strike on Friday killed at least 13 people in a border tribal area of northwest Pakistan known as a Taliban hideout, officials said.
A missile hit a house near Miranshah, the main town in North Waziristan, at 3:50 am (2150 GMT Thursday), a Pakistani security official told AFP.
"It was a drone attack. The missile targeted a house in Dandey Darpa Khel," he said, adding that the building was badly damaged.
"So far 13 bodies have been recovered," said the official, who had earlier put the death toll at nine.
"Those killed in the drone attack were all militants. Some of them were Afghan Taliban, others were local militants," another official said. There was no high-value target, he added.
Residents said militants surrounded the compound after the attack and a tractor was used to remove the debris.
The compound targeted was a Taliban office, some residents said, adding that Afghan militants also used to visit.
Friday's strike was the third in the rugged tribal terrain since a US drone missile reportedly killed Pakistani Taliban chief and feared warlord Baitullah Mehsud in neighbouring South Waziristan on August 5.
The US military does not, as a rule, confirm drone attacks but its armed forces and the CIA operating in Afghanistan are the only forces that deploy drones in the region.
Residents of Miranshah said they heard a huge noise which shattered windows and blew out doors in the town.
Dandey Darpa Khel, some two kilometres (about one mile) north of Miranshah, is known to have hideouts belonging to an Afghan Taliban leader, Jalaluddin Haqqani, and was hit in a missile attack last October which killed 11 people.
It also has offices of Mehsud's Tehreek-e-Taliban Pakistan (TTP) based in South Waziristan.
Shortly after Friday's strike, militants opened fire on a military checkpoint near Miranshah, residents and local officials said.
The firing continued for some time and security forces retaliated, an official said, adding that three militants were killed and two paramilitary troops wounded in crossfire.
Islamabad publicly opposes suspected US strikes, saying they violate its territorial sovereignty and deepen resentment among the populace. Since August 2008, around 51 such strikes have killed more than 517 people.
But many analysts and observers believe that the government gives tacit support to the punishing attacks, as it shares the US goal of eliminating Mehsud's network, blamed for scores of deadly attacks in nuclear-armed Pakistan.
The Pakistani military in late April launched a major offensive against the Taliban in the northwest, targeting the rebels in the districts of Swat, Buner and Lower Dir after the insurgents advanced perilously close to the capital Islamabad.
Last month the military claimed to have cleared the area of the Taliban threat, and vowed to turn their attention to the mountainous tribal belt along the Afghan border where Mehsud and his Tehreek-e-Taliban Pakistan have thrived since 2007.
Pakistani and US officials accuse Mehsud of masterminding the 2007 assassination of ex-prime minister Benazir Bhutto and a string of other attacks that have killed hundreds of people here over the last two years.
Washington alleges Al-Qaeda and Taliban rebels who fled Afghanistan after the 2001 US-led invasion are holed up in the semi-autonomous tribal belt.