Bombings killed 10 people and wounded at least four in Pakistan on Thursday, including an attack in a police complex in the capital the same day lawmakers huddled for a private briefing on the militant threat facing the country.

The deaths happened in the nation's volatile northwest, where Al Qaeda and Taliban militants have established bases near the Afghan border.

Four children, two police and four prisoners died when a roadside bomb exploded under a prison vehicle in the Dir region, government official Sher Bahadur Khan said. Initial reports indicated a school bus was caught in the blast, but others said the children were walking. Ten people were wounded.

In Islamabad, an apparent homicide car bombing severely damaged an anti-terror squad building and wounded at least four police in the heavily guarded Police Lines neighborhood. The explosion occurred just moments after a man delivered candy to the facility and police were examining whether the events were linked.

Some body parts were found that might belong to a homicide bomber, Islamabad Police Chief Asghar Gardaizi said.

In recent weeks militants have stepped up attacks on security, government and Western targets in Pakistan, reaching well beyond the northwest border areas. A Sept. 20 homicide truck bombing in Islamabad killed 54 and severely damaged the Marriott Hotel.

The latest incident in Islamabad happened amid tight security for the briefing of lawmakers at the Parliament building. No one immediately took responsibility.

Ambulances streamed into the smoke-filled police complex after the blast.

The front section of the three-story, red-brick building was destroyed and a staircase had collapsed. Shoes were strewn among the rubble. Gardaizi said at least four people were hurt; others put the wounded toll as high as nine.

Police commando Gulshan Iqbal told The Associated Press he was sitting at a nearby barrack when a "Suzuki car hit the anti-terror squad barrack and exploded with a big bang."

He said the main building was largely empty because many officers were guarding Parliament and other areas of Islamabad.

"About 10 people were inside at the time, and we saw six or seven injured," he said.

Gardaizi said a man in a green car had driven up to the building, entered and handed boxes of candy to a person inside. He later left the building and within moments the explosion occurred, Gardaizi said.

It was unclear what happened to the delivery man. Gardaizi said authorities would probe why a civilian vehicle was allowed in the area.

The attacks in Islamabad and Dir drew condemnation from the prime minister of Pakistan, where the military says homicide attacks have killed nearly 1,200 people since July 2007, most of them civilians.

The statistics also said 1,368 security force personnel had been killed since late 2001, when Pakistan's former military ruler, President Pervez Musharraf, allied the country with Washington in its war on terror.

The young civilian government called the joint Parliament session in an effort to build a national consensus on the Muslim nation's role in the U.S.-led war on terror.

Many in Pakistan believe the alliance with the U.S. has increased violence in their nuclear-armed country. The U.S. has shown impatience with Pakistan by launching cross-border missile strikes in the northwest, where Al Qaeda leader Usama bin Laden is rumored to be hiding.

On Wednesday, lawmakers were shown images of militants killing people, according to two attendees who requested anonymity because like others at the meeting they were sworn to secrecy. Statistics on militancy were also given, one said, declining to divulge specifics.

Ahmed Shujaa Pasha, an army general tapped to take over Pakistan's main spy agency in the coming days, gave the briefing. The topics included Pakistan's military offensives against insurgents in tribal regions bordering Afghanistan.

Speaking in general terms, some politicians said the briefing Wednesday was superficial.

"It was more like the description of the symptoms than diagnosis of the disease," Khurram Dastagir, a member of the opposition party of ex-Prime Minister Nawaz Sharif, told Dawn News TV. "I am seeking to find out what is causing this extremism and how did it come about."

Attorney General Sardar Latif Khosa, said Thursday's session was arranged to allow lawmakers to ask questions. He said the meetings could go on for several more days.

Concrete barriers and barbed wire ringed a wide perimeter around Parliament. Members of the media were not allowed in.