KARACHI, March 7: Police groped around in the dark as they failed to make a breakthrough even on Tuesday in the suicide car bombing that occurred on last Thursday killing a US official and four others including the suicide bomber near the American Consulate in Karachi.

Five days have lapsed since the blast and investigators are still clueless about the perpetrators of the attack that left no obvious evidence for tracking them down.

Local investigators had collected all available evidence from the site of the attack and the remaining were gathered by FBI agents who reached the spot later.

Investigators believed that the group involved in the car bombing was trained and well-organized from the fact that the carried-out attack was well-planned.

In past bomb explosions, the police reached the suspects after investigating into the chassis or engine numbers of the cars or from mobile phone SIMs used in the attacks.

However, the perpetrators in this recent incident seemed to have learned a lot from past incidents, and had tried to hide possible clues after carrying out the attack.

The investigators also think that the type and quantity of explosive used in this attack had never been used in previous bombings.

Though the type of explosive is yet to be ascertained, it ignited fire around the area where it exploded, contrary to past explosions, where there was no fire breakout.

In Thursday’s blast, more or less 22 vehicles parked in the vicinity had caught fire due to the heat that emanated from the explosion.

Two of the important evidences i e the cellphone and car used in the blast could also not help investigators to advance their probe in tracking the culprits. Sources said that the two important evidences were destroyed.

The car used in the blast belonged to Naseem Sajid of Lahore. It was snatched at gunpoint in May 2005 and was still untraced. Mr Sajid was shot at on resistance by the bandits and was being treated abroad. The Lahore police could not obtain the sketches of those who had snatched the car at gunpoint.

Investigators could not find the SIM of the suicide bomber from the place of the incident. They although did obtain the record of calls made within a span of half-an-hour till the blast.

They sorted out those numbers, from which no conversation was made since the explosion. But they failed to meet any success in tracing the number of the suicide bomber.

The fingerprints of the limb of the suicide bomber could also not be obtained, as the fingers were charred and their linings were broken, sources said.

Surveillance cameras have captured the clips of the bomber from a considerable distance but his face was not much visible.

A senior investigator confidently said: “We will get the photograph of the suicide bomber soon and establish his identity in a couple of days.”