Preliminary investigations have indicated that the RDX was supposed to be used by a Punjab-based terrorist outfit to target several VIPs living in the Capital.

The RDX haul has been dubbed as the largest ever in Delhi. The last time that RDX was used in the Capital was in the bomb blast at Lajpat Nagar Market in August 1996.

Apart from RDX, four ABCD timers -- which can trigger an explosion even 194 days after the bomb has been set up -- was found, which senior officials said, is equally significant because this is the first time that such equipment has been found in the Capital.

The driver of the truck, which was coming from Batala in Punjab, Raj Kumar, and his companion, Gurcharan, have been arrested. The RDX, timers, a dismantled AK-47 assault rifle, two Chinese-made pistols, 230 cartridges, eight hand grenades, and 10detonators were concealed in the space between the rim and the tyre of the spare wheel.

The explosives were being smuggled into Delhi at the behest of three militants from the Babbar Khalsa group -- terrorist outfit from Punjab who are currently lodged in Tihar Jail.

The police commissioner, however, refused to comment on the possibility of some consignments of RDX having reached Delhi in the recent past. ``As we are yet to question the accused in detail, it would not proper to comment at this stage,'' he said.He also ruled out the involvement of this group in the bomb blast at ITO on January 9 and the one in Kailash Colony on June 27.DCP (Crime) Karnal Singh explained that an ABCD timer consists of four separate wires. The various combinations, which are followed while joining the wires, sets the time period for the explosion to take place anytime up to 194 days.