PESHAWAR, Pakistan — A suicide bomber rammed his explosive-laden car into a police station early today, killing at least six people and wounding almost 70, a sign that insurgents still have the power to strike despite a major military offensive in Pakistan’s northwest.

The bombing destroyed the police station in Bannu district and many officers were still buried in the rubble, said police chief Mohammed Farid. At least one of the dead was a police officer, and another was a prisoner held in the lockup.

Pakistan’s mountainous, lawless northwest region along the Afghan border — where the government holds little control — is a favored area for insurgents to plan attacks on U.S. and NATO troops in Afghanistan, as well as on Pakistani security forces and government workers.

Taliban spokesman Qari Hussain Mehsud phoned The Associated Press to claim responsibility for the bombing. “We have broken the silence as the government did not understand the pause in attacks, and from now there will be an increase in the number of suicide bombings,” he said.