Four foreign militants were killed in a suspected U.S. missile strike in northwest Pakistan, two Pakistani intelligence officials said Tuesday.

The men were identified as Abu Qasim, Abu Musa, Abu Hamza and Abu Haris, said the officials, who spoke on condition of anonymity because of the sensitivity of their job. It was unclear what rank the men held with the Taliban or Al Qaeda.

Officials said the death toll from Monday's missile strike rose to 20 after residents and militants pulled more bodies from the rubble of a seminary and houses in a village in the North Waziristan region.

Citing informers, they said the dead also included a wife and a sister of senior Taliban commander Jalaluddin Haqqani and at least four children. Another 18 people were wounded.

American commanders count Haqqani, a veteran of the jihad against Soviet troops in Afghanistan in the 1980s, among their most dangerous foes. He and his son, Siraj, have been linked to attacks this year including an attempt to kill Afghan President Hamid Karzai and a bold attack on a luxury hotel in Kabul.

Residents told of seeing two Predator drones in the sky shortly before multiple explosions hit the seminary and houses in the village of Dande Darba Khel on Monday morning.

A spokesman for the U.S. military coalition in Afghanistan, 1st Lt. Nathan Perry, said he had no information that he could release on the matter. He did not deny coalition involvement.

The U.S. has pushed Pakistan to crack down on insurgents, warning that they are using pockets of the northwest as safe havens from which to plan attacks on American and NATO forces in neighboring Afghanistan.

However, Pakistan has struggled to contain rising militancy within its borders, and the fledgling government has tried both peace talks and military operations to stop the insurgents.