PESHAWAR: A Taliban suicide bomber rammed a truck bomb into a Pakistani police station at dawn Wednesday, flattening the three-storey building in a massive explosion and killing five people.

The country's main Taliban faction claimed responsibility for the attack in the protected military zone of the northwestern city of Peshawar, saying it was their fourth reprisal for the US killing of Osama bin Laden in Pakistan.

Five policemen died in Wednesday's explosion, a relatively low toll given the enormity of the blast, but officials said the building normally had only a skeleton staff at the time of the attack.

An AFP reporter saw flames from the stricken building, shattered glass on the ground, pancaked rubble, burning tyres and the charred remains of at least three vehicles, including a small truck.

Constable Farid Khan, who had his shoulder fractured in the attack and was admitted to a hospital told AFP that he was saying his morning prayers inside the police station when a deafening explosion took place.

“The roof of the building collapsed with the impact of the blast,” he said, adding he could not get up because of his shoulder injury and his colleagues later took him to the hospital.

Rescuers were trying to reach four or five people believed trapped alive in the rubble, police official Mohammad Ijaz told AFP.

“It was a huge blast which completely destroyed the three-storey building,” Ijaz added, saying there were usually 10 to 15 people present at that time in the police station.

Police said another 23 people, including nine policemen and a child, were wounded in the blast.

The razed building housed the police Criminal Investigation Department and was located in the Peshawar Cantonment area just 150 metres from the US consulate. The area houses military families and security is normally tight.

Police said the attack was carried out with a small truck containing at least 200-250 kilograms of explosives, and that body parts were hurled more than 300 metres away from the blast.

“We will further step up these attacks to avenge Osama bin Laden's martyrdom,” Taliban spokesman Ehsanullah Ehsan told AFP by telephone from an undisclosed location.

“These attacks will continue until the US drone strikes and ongoing Pakistani military operations are stopped in the tribal regions,” he added.

The military rushed to seal off the area around the Peshawar police station after the 4:38 am blast.