RDX,ammonium nitrate used in bomb,confirm police

So far we dont know how the explosion was triggered,whether by a timer device or by remote control, he said.

Confirming The Indian Express report that German Bakery too had a CCTV in place,Singh said the footage was giving important clues. He said both the bakery footage and CCTV film from a nearby hotel were being looked at.

The forensic experts are working on the circuit and the trigger used to activate the bomb. According to experts,they have found some metal remnants that seem like scattered circuits. We are still working on the remnants as they could also be cellphones of the victims, an official said.

Although there was no official statement about the quantity of explosives used,sources said it was suspected that 1.25 kg of explosives was used,out of which 750 gm was RDX.

Though the composition of the bomb was fairly common of mixing a high explosive RDX with an improvised explosive ammonium nitrate with a binder petroleum jelly experts said it was possibly the first time an Indian Mujahideen IM module,if its role is confirmed in the blast,has used RDX.

In all the earlier blasts,the IM has used ammonium nitrate as the main explosive.

It also indicates that if the probe does indeed point towards the IM,then this blast will need to be bookmarked as the first time that the terror group has used RDX, said an expert.

Sources said IM founder Riyaz Bhatkal or his brother Iqbal based in Pakistan may have helped in getting the RDX across.

There is also a possibility that some new group may be involved in the blast, said a senior officer from an investigative agency.