Though the Central Forensic Science Laboratory (CFSL) is yet to submit its report, bomb disposal experts said that the contents showed traces of potassium chlorate or ammonium nitrate and sulphuric acid.

The explosive was then packed inside an iron container with iron filings and pellets. Both these compounds were found to be used in last year's explosions.

A similar device was used in the explosion at Kailash Colony on June 27 this year. The explosive used in the bomb blast inside a bus at ISBT on July 26, however, was ascertained as RDX.

No one has claimed responsibility for yesterday's blasts so far. And the police are yet to obtain any clues to the identity of the group behind the explosion. The possibility of Punjab militants or ISI-backed Kashmiri militants being behind the incident is being explored.

DCP (Central) Ajay Kashyap, who is part of the special team probing the blast said: ``The modus operandi is also similar. The miscreants chose a busy area to explode the device so that they could create more panic.'' Delhi Police Commissioner V.N. Singh today constituted the special team headed by Special Commissioner (Intelligence) S. Ramakrishnan. The team also includes DCP (special cell) Ashok Chand, besides Kashyap and others.

Singh announced a reward of Rs 50,000 to anyone giving information about the blast and previous explosions at ITO on January 9, Kailash Colony and ISBT this year.

Another special team has been constituted, which will be stationed in the Walled City in view of the coming festival season.

The police commissioner has ordered strict vigilance in all sensitive areas in the Capital, including railway stations, inter-state bus termini, and public transport. Credentials of new tenants and occupants of newly built houses will be verified.

He has also requested the public to inform the police in case they come across any strange object or person. Checking of vehicles likely, to be used by terrorists, would be also stepped up.

The team probing yesterday's blast has been asked to recheck the leads achieved in last year's explosions. The 15 persons who were arrested in this connection will be questioned once again. Meanwhile, 16 of those injured last evening, were discharged from the LNJP hospital today. One person is still recuperating. The police have also identified the body of the person who died in the explosion as Vikram Mahato, a resident of Bihar.