Pakistani officials are trying to establish which and how many militants loyal to Baitullah Mehsud, leader of the Taleban in Pakistan, were among the estimated 45 to70 people killed in American drone strikes on his stronghold on Tuesday.

A US drone fired at least three missiles at a Taleban training camp in the Makeen area of the tribal region of South Waziristan on Tuesday morning, killing at least seven militants, including a commander called Niaz Wali, according to local officials.

Another drone then fired at least four missiles in the evening at a funeral prayer meeting for Wali, attended by hundreds of militants and local villagers, the officials said.

Security sources told The Times that Sangin Khan, an Afghan Taleban commander, was believed to be among the dead.

However, earlier reports that those killed included Qari Hussain, a deputy to Mr Mehsud responsible for training suicide bombers, proved to be untrue.

There were conflicting reports, too, over whether Mr Mehsud himself had attended the funeral and had narrowly avoided being caught up in the attack.

The exact death toll from the second attack was unclear but estimates from local officials and residents for the two strikes combined ranged from 45 to 70.

Jalaluddin Mehsud, who lives near the area and knew many people at the funeral, told The Times that 67 people had been killed, including 18 civilians.

The attack on the funeral appears to have been the bloodiest US drone strike yet on Pakistan – and the fourth one in three months on the heartland of Mr Mehsud, who declared himself leader of the Pakistani Taleban in 2007.

It came as Pakistani forces also pounded the area — seen as an al-Qaeda sanctuary and possible hiding place for Osama bin Laden — with air strikes and heavy artillery in preparation for a ground attack on Mr Mehsud.

Pakistan blames him for a string of recent suicide bombings, as well as for the assassination of Benazir Bhutto, the former Prime Minister and wife of the current President, Asif Ali Zardari, in December 2007.

America calls him al-Qaeda’s main “facilitator” in Pakistan tribal areas and has placed a bounty of $5 million on his head.

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