Pakistani officials say at least 500,000 people are expected to flee a northwestern town, fearing escalating violence between troops and Taliban militants.

North West Frontier Province's information minister (Mian Iftikhar Hussain) says authorities are establishing temporary camps to house those evacuating the town of Mingora in Swat Valley.

Panicked residents were seen leaving the area, after the military lifted a curfew allowing civilians to relocate. Residents say militants were patrolling parts of Mingora and had placed landmines along key routes.

Pakistani troops launched an offensive against the Taliban last month after militants violated a peace deal in the region that required them to disarm.

Elsewhere in the northwest, Pakistani police say a suicide bomber rammed his car into a military vehicle at a checkpoint near the city of Peshawar, killing at least four civilians and one soldier.