A homicide bomber killed at least 50 people inside a mosque packed with holiday worshippers at the residential compound of a former top security official for President Pervez Musharraf, police said.
Pakistani police on Friday raided an Islamic school and arrested seven students but officials would not confirm if the raid was related the attack, which had occurred just hours earlier.
• Click here to view photos.
Suspicion likely will focus on the pro-Taliban or Al Qaeda militants active in northwest Pakistan — near the Afghan border — where the attack occurred. The attack also deepened the sense of uncertainty in Pakistan as it heads into Jan. 8 parliamentary elections.
As interior minister, Sherpao was deeply involved in Pakistan's efforts to combat the Taliban and drive out Al Qaeda. A candidate for parliament, he left office last month as a caretaker government took over ahead of the elections.
The bombing, which left bloody clothes, shoes and pieces of flesh scattered across the house of worship, was the second homicide attack in eight months apparently targeting Aftab Khan Sherpao, who escaped injury.
Musharraf condemned the blast and directed security and intelligence agencies to track down the masterminds, the state Associated Press of Pakistan reported.
After the bombing, dozens of police and intelligence agents raided an Islamic school in the nearby village of Turangzai and arrested seven students, some of them Afghans, two police officials said, speaking on condition of anonymity because they were not authorized to talk to the media.
The blast deepened the sense of uncertainty in Pakistan ahead of Jan. 8 parliamentary elections, which Sherpao, as head of the Pakistan Peoples Party-Sherpao, is contesting.
The bombing turned a prayer service crowded with hundreds of people celebrating the Islamic holy day of Eid al-Adha into a scene of carnage at the mosque inside Sherpao's residential compound in Sherpao, a village 25 miles northeast of the city of Peshawar.
The bomber was in a row of worshippers when he detonated the explosive, provincial police chief Sharif Virk said.
"There was blood and body parts everywhere. There was panic everywhere. People were running. Some people were injured in the chaos," said Iqbal Hussain, a police officer in charge of security at the mosque.
District mayor Farman Ali Khan said between 50 and 55 people were killed, and authorities were collecting information on their identities. Local police chief Feroz Shah said over 100 were wounded.
Witnesses said the dead included police officers guarding Sherpao, who was praying in the mosque's front row at the time of the attack. He was not harmed, but one of his sons was wounded.
The hospital in Peshawar was wracked with chaos as the injured arrived in pickup trucks, ambulance sirens wailed and wounded screamed for help. The bomb contained between 13 and 17 pounds of explosives and was filled with nails and ball bearings to maximize casualties, said the head of the bomb unit at the scene, who declined to give his name.
A bulldozer was brought in to help volunteers with shovels dig graves for the dead next to the mosque.
Minhaj Khan was digging a grave for the dismembered body of Shah Jee, a 28-year old father of two from the village.
"He was a poor laborer. Now who will look after his family?" he asked. "It is nothing but extreme cruelty to kill people on such a holy day for Muslims."
Hussain, the police officer, said everyone entering was forced to pass through a body scanner and was searched with metal and explosive detectors. "We don't know how the bomber got in," he said.
Hamid Nawaz, the current interior minister, insisted there was no security lapse.
"All possible care had been taken, there was no lapse as such ... but such an incident can happen at such a gathering," Nawaz told Aaj TV.
After the blast, Sherpao's house was protected by about a dozen police and paramilitary troops.
As interior minister, Sherpao was Pakistan's top civilian security official in the administration recently dissolved ahead of the elections.
Islamic militants have repeatedly targeted top figures in the government of Musharraf, a key ally in the U.S.-led war on terror. In April, Sherpao was slightly wounded by a bomber, and Musharraf himself narrowly escaped assassination in two bombings a few days apart in December 2003.
Taliban and Al Qaeda fighters have extended their influence over tracts of Pakistan's volatile northwest in the past two years and in recent months have launched numerous homicide attacks, usually targeting security forces and their families.
The army says the most recent attacks could be retaliation for a military operation against militants in the Swat valley, where it claims to have killed about 300 militants since last month.
The violence came as Pakistan struggled to emerge from months of political turmoil.
Musharraf recently declared emergency rule for six weeks — a move he said was necessary to combat rising Islamic extremism, but was widely seen as a ploy to prolong his own presidency. Thousands of his opponents were rounded up and Supreme Court justices fired.
On Friday, police rearrested prominent opposition lawyer Aitzaz Ahsan, according to his son, Ali Aitzaz. Aitzaz Ahsan, who had been at the forefront of a lawyers' protest movement, was released Thursday for three days for the holy day, but detained again after just one day.