ISLAMABAD, Oct 9: A suicide bomber rammed an explosive-laden car into headquarters of the Anti-Terrorist Squad of police on Thursday, injuring eight policemen.

The explosion partly destroyed a three-storey block of the Anti-Terrorist Squad building and left a four-foot deep crater.

The bomber struck a target in a high security zone, though the city has been on high alert in the wake of a suicide truck bomb that killed 55 people and destroyed the Marriott hotel on Sept 20.

Very few policemen were in the building at the time because they were on duty guarding the parliament.

The injured policemen were taken to different hospitals of Islamabad.

A spokesman for the Pakistan Institute of Medical Sciences told Dawn that four policemen — Assistant Sub-Inspecor Faizullah, constables Naveed, Tahir and Wakil Khan -- were brought to the hospital and were in stable condition. An injured policeman Asif was admitted to the Federal Government Services Hospital.

The adviser to Prime Minister on Interior, Rehman Malik, has ordered an inquiry into the bombing.

According to witnesses, a private car bearing a green number plate entered the police headquarters building through Gate No 3 and struck the vehicle against the building.

However, police said the bomber had parked the vehicle outside the three-storey ATC building and walked inside and gave a box of sweets to Muharar Tahir, who was stated to be his friend.

A mighty explosion followed, destroying a portion of the building and injuring seven policemen.

Police constable Aamir Raza said a green car bearing a yellow number plate 6949 was parked outside the building and suddenly a huge blast took place.

The venue of the blast was presenting a terrible look, with injured policemen lying on the floor amid rubbles and shattered windowpanes. The sound of the blast was heard several kilometres away.

A senior police official told Dawn that a suspected suicide bomber had been visiting Muharars Shafiq and Tahir of the ATS and telephoned them two days ago.

“In his latest telephone call, the suspect had intimated one of his friends that he wanted to come to his office,” he said.

On the request of the suspect, Muharar (diarist) Shafiq reportedly intimated the security staff at Gate No 3 that his guest was coming and he should be allowed to come inside. The suspect delivered a box of sweets at the gate and then drove close to the ATS building. The authorities are questioning two injured Muharars who had “friendly relations” with the bomber.

The official said remains of the bomber had been recovered from the scene of the blast.

Eight policemen, including a DSP and an inspector, were suspended and taken into custody in connection with the suicide bombing.

Two of the detained policemen were injured cops who had reportedly asked security staff at the entrance gate to allow their “guest’s vehicle” into the building and accepted sweet boxes brought by the bomber.