At least one policeman was killed while two others were injured when unknown militants stormed a police station here in Bannu on Monday morning, said police.
Four militants were also killed in the incident, police added.
District Police Officer of Bannu said a police constable embraced martyrdom in the incident.
According to the media reports, terrorists, in their bid to enter the police station, hurled two hand grenades and resorted to indiscriminate firing.
The district administration sought help from the Pak Army for law and order in the city.
DCO Atif ur Rahman, taking notice of the alarming situation, imposed curfew in the city for indefinite period.
All the main roads leading to the city was blocked by police and security forces in fear of more possible attacks by militants, said media reports.
The attack took place when six to eight gunmen, according to eyewitnesses, launched an attack on the police station.
Hand grenades and heavy weapons were used in the attack, said reports, adding that two blasts were first heard at the police station, followed by fierce firing.