The bomb that exploded in Pune last week was made by mixing ammonium nitrate with potassium chlorate and small ball bearings were used as shrapnel to inflict injuries, but there was no gelatin or RDX in it, Maharashtra ATS said today.

"The forensic reports we have received suggest that the Improvised Explosive Device (IED) which exploded (in Pune) was a mixture of ammonium nitrate and potassium chlorate. Small ball bearings, like the ones used in cycles, were used as shrapnel. But there was no gelatin, RDX or Trinitrotoluene (TNT) in the bomb," Anti-Terrorism Squad (ATS) chief Himanshu Roy said.

An analogue clock was used as a trigger for the low intensity bomb, he said. The IED would have caused much more damage had the perpetrators not miscalculated their move, he observed.