Two US missile strikes deep in Pakistan's northwest tribal belt killed up to 16 militants, with more bodies recovered from the wreckage on Thursday, security officials said.
Two successive bombing raids by unmanned spy planes hit a building and vehicles late Wednesday in North Waziristan, a bastion of Taliban and Al-Qaeda-linked militants near Pakistan's border with Afghanistan.
It was the latest in a surge of drone strikes by US aircraft, as Washington pursues the insurgents it says are using Pakistan's mountainous tribal belt to plan and launch attacks on US and NATO troops in neighbouring Afghanistan.
The missile strikes come with Afghan President Hamid Karzai in Islamabad for talks with Pakistani leaders on tackling Islamist militants waging bloody insurgencies on both sides of the border.
"The death toll in the drone strikes has risen to 16 as four more bodies were found," a senior security official in the region told AFP.
"At least five of those killed are foreign militants."
The official did not reveal the nationalities of the dead, but the term "foreign militant" is often used to refer to Al-Qaeda-linked fighters.
Seven militants were killed in the first strike targeting a compound and a nearby vehicle in Mizar Madakhel village, about 50 kilometres west of Miranshah, the main town in North Waziristan.
Nine more fighters died in a second strike which hit shortly after as militants pulled bodies from the rubble of the first bombing raid.
Another official put the overall death toll at 14, but said US drones were still hovering over the area while witnesses said militants had cordoned off the bombing site and were scouring the rubble for more bodies.
It was the deadliest US missile strike since February 2, when a swarm of drones fired about 18 missiles into militant hideouts and training camps in North Waziristan, killing 31 people, mostly Islamist militants.
The strikes have killed more than 800 people in Pakistan since August 2008, with a surge in the past year as US President Barack Obama puts Pakistan at the heart of his fight against Al-Qaeda and the Taliban.
Officials in Washington say the strikes are a vital tool and have killed a number of high-value targets including Pakistani Taliban chief Baitullah Mehsud, but the bombing raids fuel anti-American sentiment in Muslim Pakistan.