ISLAMABAD: RDX, a highly explosive material, was used in the fruit and vegetable market bombing, officials privy to the investigation told Dawn on Friday.

At least 24 people were killed and 122 others injured when a bomb tore through Subzi Mandi in the federal capital on Wednesday.

The bomb contained five kilograms of RDX, along with nuts and bolts, the officials said.

RDX, or research department explosive, is a powerful nitroamine widely used in military and industrial applications. It is more powerful than TNT and saw wide use in World War II.

This was the third terrorist attack, out of 23 in Islamabad, in which RDX was used. Earlier, it was used in a suicide attack on Marriot Hotel in September 2008, they said. Al Qaeda was involved in that bombing, they added. A suicide jacket which a bomber detonated during the attack on Islamabad’s district and sessions court on March 3 also contained RDX, along with TNT (trinitrotoluene) and PETN (pentaerythritol tetranitrate).

The officials said identification of the explosives would help investigators find out whether any militant outfit was behind the attack or not. Intelligence agencies have been approached to match the device with the profiles available with them of different militant outfits. The process would take some time, maybe weeks, they said. The capital police’s Crimes Investigation Department had no record of militant outfits using RDX, they added.

They said C4 (a common variety of plastic explosives) had also been used in previous attacks in Islamabad.