ISLAMABAD, Oct 10: A joint investigation team has drawn a sketch of the suicide bomber who drove his explosive-laden car close to the Anti-Terrorist Squad building and blew himself up, Dawn has learnt.

The sketch has been prepared on information gained from policemen who encountered the bomber and it resembles the photograph which was pasted on his bogus identity card.

However, the sketch of the bomber has not been revealed to the media.

The bomber had his vehicle blown up at the building after evading the security at the entrance on Thursday, injuring at least eight policemen and damaging the ATS wing building.

The team has also traced the public call office (PCO) located in Islamabad from where the suicide bomber had telephoned to the Muharar ATS and told him that he was coming to his office to deliver a sweet box to his boss.

The suicide bomber, who identified himself as Musa Khan at the entrance gate, was about five-feet and 4-inche tall with black small beard and wearing white shalwar kameez.

Aged between 22 and 23 years, he seemed to be from Punjab but was speaking Urdu, the source said.

Head Constable Tahir Mehmood and constables Wali Sardar, Noor-ur-Rehman and Mohammad Ashraf, deployed at gate no. 3, stopped the car and got his identity card and referred him to Naib Muharar Shafiq who reportedly told the security staff at the gate to allow him in.

The source said pieces of the suicide bomber recovered from the scene of the blast would be sent to laboratory for DNA test.

The investigating team has also recorded the statements of all the six policemen who were booked after the terrorist attack. They are the four security guards deployed at the entrance gate and two ATS wing staff member - Naib Muharar Shafiq and Tahir, reader to DSP ATS.

The team has also picked up a man who it believes is an important achievement. However, his identity has been withheld. The car used by the suicide bomber was snatched from Karachi last year.