ISLAMABAD, Oct. 2 (Xinhua) -- A policeman was killed and at least three others injured in a bomb attack on a police vehicle in Pakistan's northwest Khyber Pakhtunkhwa province on Thursday, police said.

The incident happened in the Qamar Deen chowk area of provincial capital city Peshawar, Capital City Police Officer Peshawar Mian Saeed Ahmad told media.

The explosion occurred when an improvised explosive device exploded near the vehicle of the police personnel who were conducting routine patrols in a busy market area, the official said.

Following the blast, police cordoned off the area and launched a search operation in the surroundings to arrest culprits.

No group has claimed responsibility for the attack yet. ■