The two bombs recovered on Sunday. Picture by Eastern Projections

Guwahati, Aug. 4: Police last night “foiled” an attempt to blow up the Kamakhya-Jogighopa railway track when they recovered two powerful bombs, each weighing 7kg, near Palashbari on the outskirts of the city.

Though the needle of suspicion points towards Ulfa, the outfit that has turned blasts before Independence Day into almost an annual ritual, the use of nitro-cellulose, a highly flammable compound in the making of the bombs has also brought into focus militant groups backed by Pakistan’s Inter-Services Intelligence (ISI).

Some years back, the US had claimed that al Qaida was using nitro-cellulose in bombs.

The use of such an improvised chemical by Ulfa has come as disturbing news for Assam police.

The superintendent of police, Kamrup, Debojit Hazarika, said acting on a tip-off, the police were scouring the railway track in the Moniari area for bombs. It falls under Palashbari police station.

Laboratory tests have confirmed that the bombs were made of nitroglycerine-nitrocellulose and ammonium nitrate with five detonators connected to each of the bombs, the SP said. “At this stage of investigation, the hand of ISI-backed Islamic groups also cannot be ruled out.

“We suspect that the bombs were kept by the militants to blow up some trains or the railway tracks. The militants could have been waiting for an opportune time to fix the timer and then plant the explosives on the nearby track. We have come to know that two youths had left a bag there. A hunt is on to apprehend them,” Hazarika said.

He said this was the first time the Kamrup police have recovered a bomb made up of nitro-cellulose. Nitroglycerine-nitrocellulose was found in the bombs in semi-liquid gel form.

The SP said that since there were not many splinters in the bombs, they were possibly meant to blow up railway tracks, bridges or culverts and not trigger blasts in crowded places.

The presence of ammonium nitrate, used in the recent serial blasts in Bangalore and Ahmedabad, in the bombs has made the police keep tabs on sale of the fertiliser easily available in the market.

The police are likely to issue a directive to wholesale traders of ammonium nitrate to maintain records of persons buying it and the amount of fertiliser sold.

As it is not always easy to smuggle RDX, outfits like Ulfa find it convenient to use ammonium nitrate, its most suitable substitute for making powerful bombs.

Ammonium nitrate is easy to procure as the chemical is not a banned substance.