The policemen from Levies, a police force consisting of tribesmen, were abducted late Monday in Bajur, a tribal region bordering Afghanistan, a military statement said.
After the six policemen were seized, militants blew up the building they were based in near Khar, Bajur's main town, said Maj. Mamoor Khan, an official with Levies, which is responsible for security in the area.
Bajur is a rugged region where security officials say al-Qaida- and Taliban-linked militants operate. Militants have been blamed for attacks on security forces in the area.
Pakistan - a close ally of the U.S. in its war against terrorism - has been battling increased militancy in its tribal regions, where a recent U.S. intelligence report indicated al-Qaida may be regrouping.
In Swat, a former tourist destination north of Bajur, security forces have been battling supporters of a pro-Taliban cleric in recent weeks.
Since Nov. 24, when the army began a crackdown on militants in Swat, fighting in the region has killed 230 fighters, army spokesman Maj. Gen. Waheed Arshad said.
Twenty civilians have also died in the violence and 90 militants have been arrested, the Dawn News TV channel reported, quoting army Maj. Gen. Naseer Janjua.