The explosive material used in the twin blasts in the temple city of Varanasi was ammonium nitrate and not RDX, official sources said in New Delhi.
The sources said the ammonium ntrate, which is readily available in the old market places of any major city, was packed in the pressure cooker, which serves as splinters as the body is made of pressurised steel.
Electric current is passed into the explosive material using the batteries to charge it and causes sparks before it first breaks into a minor fire and then explodes with a bang, the sources said.