Three heavily armed militants were killed after they stormed a district police chief's office in northwest Pakistan on Saturday, triggering a two-hour standoff with security forces, during which nine persons were injured.
Two of the attackers detonated their suicide vests inside the police compound at Dera Ismail Khan while one more was gunned down by security forces.
Police officers said they believed between five and eight militants were involved in the assault and a search had been launched for the attackers who escaped.
Seven policemen and two passers-by were injured in the attack and subsequent exchange of fire between the militants and security forces.
The Pakistani Taliban has claimed responsibility for the attack.
The Taliban had recently killed 15 paramilitary troopers they had abducted in the country's northwest and pledged to carry out attacks to take revenge for operations by security forces.
The militants, who were wearing police uniforms, used ladders to clamber over a wall at the back of the police compound.
They then lobbed several grenades and fired indiscriminately with automatic weapons. Reporters at the site said they had heard at least seven to eight explosions and intermittent firing. The district police chief's office is located in a high-security zone near a court complex and lawyers' offices.
Security forces cordoned off and evacuated the area. Army troops were called in to help police commandos flush out the militants. Footage on television showed soldiers taking position on roofs of houses near the police compound and firing at the militants.
Smoke could be seen rising from the compound.
Dera Ismail Khan is located close to South Waziristan tribal region, which was a key stronghold of the Pakistani Taliban till the army conducted an anti-militancy campaign in the area in 2009.
