A suicide bomber has detonated a vehicle packed with explosives outside the home of a top anti-terror police officer, killing at least eight people and leaving a crater 10ft deep.
The policeman targeted in the bombing in Karachi, Chaudry Aslam, who was unharmed, is tasked with cracking down on the Taliban and other militants.
He appeared on television shortly after the attack to blame the Pakistani Taliban. "This is a cowardly act," said Mr Aslam. "I'm not scared. I will not spare them."
The bomb exploded as many children were heading to a school near Mr Aslam's home in the Defence neighbourhood of Karachi, a wealthy residential area that rarely experiences militant attacks or other forms of violence that plague the city.
The eight people killed in the attack included six policemen guarding Mr Aslam's house, one woman and one child, Mr Aslam said. He estimated that at least 440lb of explosives were used.
Television footage showed extensive damage from the blast. The front of one concrete building was blown away and rubble littered the streets amid the burned wreckage of cars.
Mr Aslam is a senior officer in the Crime Investigation Department, which works to arrest Taliban fighters and other militants in Karachi, a bustling city that is home to some 18 million people and is also Pakistan's main commercial hub.
Karachi has not seen as many militant attacks as other major cities in Pakistan, but it is believed to be home to many Taliban militants who have fled army operations in the north west near the Afghan border.
Former Pakistani cricket captain Moin Khan passed by the site of the attack shortly after the blast. "Thank God it was half an hour before school time," he said. "It was horrible. I saw four bodies. Broken pieces of vehicles were scattered more than 100 feet."
A purported Taliban spokesman, Qari Nusrat, claimed responsibility for the attack. "Our men in Karachi carried out this attack," he told the Associated Press by telephone. Nusrat said he was based in Pakistan's South Waziristan tribal area near the Afghan border and was asked by the Pakistani Taliban's official spokesman, Ahsanullah Ahsan, to contact the media.