Missiles fired from U.S. drone aircraft hit a seminary and houses associated with a top Taliban commander on Monday, killing at least nine people, including militants and civilians, officials and witnesses said.

The explosions occurred in a village in North Waziristan, a militant stronghold in Pakistan's northwestern wild tribal belt and a possible hiding place for Usama bin Laden and Al Qaeda No. 2 Ayman al-Zawahri.

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 in what appeared to be part of a stepped-up U.S. campaign against militant havens in Pakistan's tribal areas along the border with Afghanistan.

The targets were linked to Jalaluddin Haqqani, a veteran of the jihad against Soviet troops in Afghanistan in the 1980s who American commanders count among their most dangerous foes.

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.

Haqqani 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. 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 in northwestern Pakistan. The intelligence official said 12 people died — three suspected foreign militants, two local men, four women and three children — when several missiles hit the seminary and adjacent houses in the village of Dande Darba Khel.

Another 15 people — mostly women and children — were injured, he said, citing informers.

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 had been there at the time, Uddin said.

Pakistani troops had raided the seminary at least three times in the past.

Maj. Murad Khan, an army spokesman, confirmed only that blasts had occurred in Dande Darba Khel and that a dozen people were injured. He said the cause of the explosions was under investigation.

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

Injured women and children were loaded into pickup trucks and driven toward nearby Miran Shah, the region's main town, Rahim said.

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.

A U.S.-led ground assault last week in the South Waziristan region prompted sharp protests from Islamabad and heightened speculation that Washington has given a green light for more aggressive cross-border strikes. Several recent missile attacks in the tribal belt have been attributed to U.S. forces.

Asif Ali Zardari, who won Pakistan's presidential election on Saturday, has vowed to be tough on militancy. However, many Pakistanis blame their country's close alliance with Washington for fanning the violence.

A homicide car bomber killed 35 people near the northwestern city of Peshawar during Saturday's voting.

On Monday, officials said they had arrested a youth wearing a suicide jacket in Nowshera, 30 miles east of Peshawar. The army said two soldiers seized the bomber before he could attack a security forces convoy.

Taliban militants have claimed responsibility for a string of homicide blasts and said they were revenge for ongoing Pakistani military operations in the northwest.

The army said Monday that it killed 10 militants in an overnight operation in the restive Swat valley.

It said the clash began when militants attacked soldiers with hand grenades, wounding two. Troops responded with firing mortars, rockets and artillery at militant positions.