RAWALPINDI, July 2 A suicide bomber on a motorcycle hit a bus carrying employees of the Kahuta Research Laboratories (KRL) at Choor Chowk on Peshawar Road on Thursday, injuring more than 40 people.

Police officials said only the suicide bomber was killed.

According to doctors, the condition of five of the injured was critical.

At least one woman was among the injured. No high-ranking officer was believed to be on the bus.

Windowpanes of several buildings within a radius of 150 metres were smashed.

At least 10 vehicles, including a wagon, were damaged.

The attack was described by officials as a grave breach of security in the garrison city.

Security officials said the bomber had used an explosives-laden motorcycle assembled with parts of different makes.

“It appeared that the motorcycle used by the terrorist was a down-model Yamaha, but its other parts were of different brands and makes,” an official said.

Witnesses said the bomber, who was in his 20s, rammed the motorbike into the 42-seat bus when it stopped at the traffic light at Choor Chowk at around 4.30pm. The bus was transporting employees back to the city.

Mohammad Jamil, who was injured in the attack, told Dawn that he was in his cab at the chowk when he saw the motorbike rider who was apparently in panic standing on the left side. He swiftly moved and hit his motorbike into the bus from the right side.

“As the motorbike hit the bus, a deafening explosion took place.”

There was chaos and human flesh was scattered over a large area. Shortly afterwards, ambulances and police vans blaring sirens reached the place.

Police seized some limbs, including two legs suspected to be of the suicide bomber.

Regional police chief Nasir Khan Durrani that although initial reports had put the death toll at six, it was learnt later that only the suicide bomber had been killed.According to bomb disposal experts, the bomber had wrapped about 10 kilograms of highly explosive C-4 around his body.

A similar strike had been carried out earlier in the R.A. Bazar.

There was no immediate claim of responsibility.

A police official said it was virtually impossible to search every vehicle entering the city.