A suicide bomber rammed a truck loaded with explosives into a police station in northwestern Pakistan on Sunday, killing a child and six other civilians, police said. The Pakistani Taliban claimed responsibility. The attack was the second this weekend in the Kohat area, illustrating the resilient nature of militant networks in Pakistan despite army offensives targeting their sanctuaries along the Afghan border.
At least 26 people were wounded, including six police, officials said.
Qari Hussain, a top Pakistani Taliban militant commander who allegedly trains suicide bombers, called an Associated Press reporter from an undisclosed location hours after the blast to claim responsibility.
He said the suicide blast was revenge for a recent army strike on a militant-run hospital in the South Waziristan tribal area.
Hussain and other Taliban commanders are believed to be hiding in North Waziristan to avoid the army onslaught in South Waziristan.
"Such attacks will continue in revenge for the deaths of our fellows," Hussain said.
The truck was loaded with up to 550 pounds (250 kilograms) of explosives, area police official Dilawar Khan Bangash said. It struck a concrete barrier in front of the building, which was heavily damaged, as was an adjoining school. 
Twin suicide attacks in the Kohat area on Saturday targeted refugees who were fleeing a separate army offensive in the Orakzai tribal region. That attack killed 41 people in line to register for food and relief supplies.
The victims of Saturday's attacks were among around 200,000 people who have left the Orakzai region since the end of last year, when the Pakistan army began airstrikes against militants believed to have fled there from South Waziristan.
The registration point in Kohat was managed by the local government, but was sometimes used by foreign humanitarian groups to deliver aid. There was no claim of responsibility for Saturday's bombings, which is not unusual when large numbers of Pakistani civilians die.
The registration point - essentially a small building in a dusty field - may have been hit to persuade people not to have any contact with the local administration or foreign relief groups.
The United Nations temporarily suspended work helping displaced people in Kohat and neighboring Hangu after Saturday's attack.
The bombers were men disguised in burqas, the all-encompassing veil worn by conservative Muslim women, allowing them to get close to the building without arousing suspicion, police said.
The tempo of the offensive in Orakzai has picked up since March. On Sunday, one soldier and 13 militants were killed in a clash in the Sangra area, said Jahanzeb Khan, an official in Orakzai.
