Three policemen were killed early on Thursday in a suicide car bomb attack at a police station in Pakistan's North West Frontier Province, a media report said.
The bomber blew up an explosive-laden car at Mingora police station in the restive Swat valley, the News Network International (NNI) news agency reported.
Around 20 security personnel were also injured in the blast, it said.
The suicide bomber managed to take the explosive-laden car inside the heavily-guarded compound of the police station at around 1 am, when most of the security personnel were asleep, the report said.
No group has so far claimed responsibility for the attack.