3 policemen killed, 1 injured in suicide bomb in NW Pakistan Rescuers and policemen inspect the suicide blast site in northwest Pakista...

3 policemen killed, 1 injured in suicide bomb in NW Pakistan

Rescuers and policemen inspect the suicide blast site in northwest Pakistan's Peshawar on March 15, 2012. Three policemen were killed and another injured in a suicide blast that took place Thursday morning in Pakistan's northwest city of Peshawar, said local police. (Xinhua/Ahmad Sidique)

ISLAMABAD, March 15 (Xinhua) -- Three policemen were killed and another was injured in a suicide blast that took place on Thursday morning in Pakistan's northwest city of Peshawar, said local police.

Shafqat Malik, Assistant Inspector General of police in Peshawar, said that the attack took place at about 9:30 a.m. local time when a suicide bomber blew himself up near a police vehicle in Pishtakhura area of the city.

Superintendent Police Kalam Khan who was on an inspection tour of check posts at the outskirts of Peshawar was killed right on the spot while his three colleagues in the vehicle were wounded in the blast.

Two of the injured police later died in hospital.

Police quickly cordoned off the area after the attack was reported and six suspects have been arrested from the nearby area in the search operation.

Bomb disposal squad believed that an estimated six kilograms of explosives were used in the suicide vest worn by the bomber. Ball bearings were used in the bomb to enhance the intensity of the blast, they said.

Identity of the suicide bomber is yet to be determined, said local police, adding that no group has claimed responsibility for the attack yet.

Over the last couple of days, a series of attacks on police were reported in the country.

On Tuesday night, unknown gunmen killed four policemen in Pakistan's eastern district of Gujrat, a place lying some 120 kilometers north of Lahore in Punjab province. On the same night, three cops were killed in Pakistan's southern port city of Karachi.

Local watchers believe that the recent attacks on police could be a reaction by some of the terrorist groups in the country to oppose the peace talk calls issued by the Pakistani Interior Minister Rehman Malik on Monday.

Following Thursday's attack on police in Peshawar, Rehman Malik strongly condemned the attack and ordered an immediate investigation into the incident.