Separately, two pro-government Pakistani militia leaders were killed and their bullet-ridden bodies recovered in the tribal area Bajaur, which borders Afghanistan, local officials said.
"Both the tribal elders were shot dead by gunmen. We think Taliban are involved in the incident as they have no other enmity," Saad Ullah, a local government official said.
Hundreds of people were killed in a six-month Pakistan operation against armed groups in Bajaur, which the military claimed in February to have "secured".
Pakistan's semi-autonomous northwest tribal belt has become a stronghold for hundreds of groups who fled Afghanistan after the US-led invasion toppled the Taliban regime in neighbouring Afghanistan in late 2001.