A group of militants armed with assault rifles attacked a roadside police checkpoint overnight in northwest Pakistan, killing three officers before fleeing, police said Thursday.

Axar.az informs, citing AP, officers returned fire at the checkpoint in Hangu, a district in Khyber Pakhtunkhwa province, and it was not immediately clear whether the attackers also suffered losses or injuries, District Police Chief Khan Zeb said.

An investigation and a search operation to track down the assailants were underway Thursday, he said.

Though no group claimed responsibility, suspicion is likely to fall on the Pakistani Taliban. Officials have blamed the group for similar attacks in recent years.