The target of the attack was not immediately known, Mr. Khan said, but it is generally believed that the bomber was aiming at pro-government Afridi tribesmen who have been fighting Taliban-affiliated groups in the area.

Darra Adam Khel fell under militant control about three years ago and was cleared by an army operation in 2010. But militants affiliated with Tehrik-i-Taliban, known as the Pakistani Taliban, continue to target government officials and their allies, and have also attacked minority sects. Districts near Peshawar have seen a spate of bombings in recent weeks.