At least 12 policemen were killed and a dozen others injured in an attack Saturday afternoon at a police station in northwest Pakistan, reported local Urdu TV channel Dunya.

The still image taken from a TV channel shows policemen taking part in an operation against militants near a police station in Dera Ismail Khan, northwest Pakistan, June 25, 2011. At least 12 policemen were killed and a dozen others injured in an attack Saturday afternoon at a police station here, reported local Urdu TV channel Dunya. [Ahmad Kamal/Xinhua]

All the police held hostage by the attackers inside the police station were rescued after nearly five hours of crossfire between the security forces and the attackers, said the report.

According to the local media reports, five out of estimated 10 to 12 attackers were also killed in the crossfire while the remaining militants managed to run away.

Three of the attackers were killed by police while the other two blew themselves up. The three attackers killed include one woman and two of them were of foreign nationality.

The security forces have taken control of the police station and a search operation is underway.

The attack took place at about 4:30 p.m. local time Saturday afternoon at a police station in the Kulachi area of Dera Ismail Khan in northwest Pakistan. Kulachi is a small town, some 30 kilometers east of the militancy-plagued South Waziristan.

Eyewitnesses said that handgrenade blasts and firing were heard shortly after two men and one woman with veil over her face entered the police station.

At initial stage at least six police were reportedly killed in the shootout.

Over 100 security personnel stationed nearby were called in after the attack was reported. However, the security forces reaching the site were unable to enter the police station as some 20-plus policemen were feared held hostage by the attackers inside the building.

Three blasts were heard when the security forces backed by armored vehicles tried to storm into the police station.

Several police vehicles were reportedly destroyed in the fight. Two policemen held hostage by the attackers were rescued during the crossfire.

It is not known how the remaining attackers have managed to flee the police station which was entirely surrounded by the security forces. Some local media reports said the number of attackers involved in the incident is much less than reported.

No group has claimed the responsibility for the attack yet.