ISLAMABAD, Pakistan - Missiles fired from U.S. drone aircraft hit a seminary and houses associated with a Taliban commander, killing at least nine people, including both militants and civilians, officials and witnesses say.

With violence spiraling in Afghanistan, Washington is becoming more aggressive about insurgent havens abutting the Afghan border, despite the strain it places on relations with Pakistan just as its new president takes office.

Monday's incident occurred in a village in North Waziristan, a militant stronghold in Pakistan's tribal belt and a possible hiding place for Osama bin Laden and al-Qaida No. 2 Ayman al-Zawahri.

Residents told of seeing two Predator drones in the sky shortly before multiple explosions hit a seminary and several nearby houses in the village of Dande Darba Khel.

A Pakistani intelligence official, speaking on condition of anonymity because of the sensitivity of his job, said three suspected foreign militants and two children were among the dead.

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

The targets were associated with Jalaluddin Haqqani, a veteran of the fight against Soviet troops in Afghanistan in the 1980s who American commanders now count among their most dangerous foes.

Haqqani and his son, Siraj, have been linked to attacks this year including an attempt to kill Afghan President Hamid Karzai and a suicide attack on a hotel in Kabul. Haqqani network operatives plague U.S. forces in Afghanistan's eastern Khost province with ambushes and roadside bombs.

Reports varied on casualties in Monday's attack. The intelligence official, citing informers, said 12 people died -- three suspected foreign militants, two local men, four women and three children.

A second Pakistani intelligence official gave a similar account.

Neither identified the victims further.

Rehman Uddin, a Taliban militant who said he was at the scene, said 20 people died and 18 were injured. "Some of our brothers were killed, but most are women and children," Uddin told The Associated Press by telephone.

One of the homes hit belonged to Siraj Haqqani, but neither he nor his father were there at the time, Uddin said.

A Pakistan army spokesman said only that it was investigating the cause of explosions that had injured a dozen people.

Bakht Niaz told the AP by phone that he and several other shopkeepers saw two Predator drones flying over the area before several explosions around 10 a.m.

"We got out of our shops and ran for safety," Niaz said.

Abdur Rahim, a villager, said he saw militants who refused to let him and others approach the scene, even to help, remove nine bodies from the destroyed houses near the seminary.

U.S. officials are pressing Pakistan hard to crack down on bases where insurgents plan attacks on American and NATO forces in neighboring Afghanistan and appear to be losing patience.

A highly unusual U.S.-led ground assault last week in the South Waziristan region was said to kill about 15 people and prompted loud protests from Islamabad -- even threats of a military response to any repeat -- but no public regrets from Washington. At least three other suspected U.S. missile attacks in the tribal belt have been reported in the last 10 days.

Pakistan's government is now firmly in the hand of Asif Ali Zardari, the widower of ex-leader Benazir Bhutto and head of the country's biggest political party who easily won Saturday's presidential election among lawmakers.

Zardari, who is to be sworn in Tuesday in the presence of Karzai, has vowed to be tough on militancy.

However, many Pakistanis blame their country's close alliance with Washington for fanning the violence.