Islamabad: Suicide attackers armed with guns and grenades on Friday stormed a police station in Peshawar, killing at least four policemen, including two officers, and injuring eight others, a day after a car bomb strike left 13 people dead in the northwest Pakistani city.

The militants numbering three lobbed grenades and fired indiscriminately as they forced their way into 'Kotwali' police station, located in a congested neighbourhood in the heart of Peshawar, early on Friday morning.

The attackers exchanged fire with policemen inside the building for almost 40 minutes.

Peshawar police chief Imtiaz Altaf said three policemen, including a sub-inspector, were killed instantly.

An assistant sub-inspector succumbed to his injuries in hospital, other officials said.

Eight policemen were injured and officials at Lady Reading Hospital described the condition of two of them as critical.

Altaf said the militants hurled grenades at policemen guarding the gates of the police station.

The policemen promptly responded and surrounded the attackers, who were left with "no other option but to explode them," he said.

The brazen attack on the police station came a day after a car bombing at a bus terminal in Peshawar killed 13 people and injured nearly 40 others.

The Abdullah Azam militant group claimed responsibility for today's strike and warned it would carry out more attacks to avenge US drone strikes in Pakistan's tribal belt.

Officials said the Kotwali police station was attacked because it houses a large number of security personnel.