Some 150 militants armed with rockets and automatic weapons attacked a northwest Pakistani terminal that lies along a key supply route used by U.S. and NATO troops, wounding three guards and torching eight cement trucks Sunday, police said.

Militants in Pakistan frequently attack cargo terminals and other stops used by vehicles taking supplies to Western troops in Afghanistan through the legendary Khyber Pass.

Scores of trucks have been damaged, while several people have died, adding urgency to U.S. efforts to find safer routes.

The latest attack started around 2 a.m. on the outskirts of the main northwest city of Peshawar, local police officer Gharibullah Khan told The Associated Press.

"They fired rockets and used automatic weapons and torched at least eight trailers carrying cement," he said.

A gunbattle at the scene wounded three guards, one of whom was in critical condition, Khan said.