Pakistani security officials say several people have been detained in connection with Friday's suicide bombing at a mosque in the restive northwest that killed at least 50 people.
The apparent target of the attack, former Interior Minister Aftab Sherpao, was not hurt, but his son and dozens of others were wounded.
Security officials, who declined to be named, told reporters those detained include at least one suspected accomplice and that a search is underway for a possible second.
They say investigators are also examining clothing, shoes and severed limbs of the suicide bomber in an effort to determine his identity.
Pakistani President Pervez Musharraf condemned the attack and directed security and intelligence agencies to track down those responsible.
United Nations and the United States condemned the attack on a house of worship.
The mosque, located inside Sherpao's compound near the city of Peshawar (in North West Frontier province), was crowded with worshippers offering prayers for the Muslim Eid al-Adha festival. .
The bombing was the second assassination attempt in eight months on Sherpao -- a close ally of President Musharraf, and an outspoken critic of Islamic militants.
He served as the country's top law enforcement official until last month when the government was dissolved ahead of next month's parliamentary elections.
Friday's bombing is the deadliest attack in Pakistan since October, when twin suicide bombings killed 139 people at a parade to welcome formerly exiled opposition leader and former Prime Minister Benazir Bhutto.
Over the past year, Islamic militants have repeatedly targeted the Pakistani army and top officials in the government of President Musharraf -- a key ally in the US-led war on terror.