Official sources privy to the investigations said tonight that ammonium nitrate, which has been often used by banned terrorist outfits like Indian Mujahideen, was packed inside a steel box.
The sources said a timer was also attached to the steel box and a combination of Neogel, generally used in stone quarries, and ammonium nitrate oil was used as the binding force for the Improvised Explosive Device(IED).
Four low intensity explosions rocked Pune last night while one was partially detonated and another one was found live and later defused.