The IEDs match the pattern of bombs used in earlier serial blasts. The quantity of explosives in the IEDs was not very much, NSG director-general Arvind Ranjan said.
The team of NSG bomb experts that collected samples from the scene of the Hyderabad bombings has not yet identified the timers used in bombs. The team is learnt to be facing difficulties on account of the bomb fragments getting mixed with debris from a shop selling watches nearby. As has been reported earlier, the IEDs were packed in aluminium containers.
A senior official who compared the Hyderabad bombs with the failed explosive devices planted in Pune last year, said, The Pune bombs were packed with ball bearings, but this one did not have any kind of shrapnel. It had been made lethal with the help of either kersoene or petrol. Both urea and ammonium nitrate were used.
The IEDs in Pune, put together with commercially available ingredients and technical ingenuity and planted on cycles, had failed to explode due to extra moisture, officials said.
According to data collected by the NSGs National Bomb Data Centre, 48 civilians and 65 security personnel were killed and 261 civilians and 158 security personnel were injured in IED blasts in India in 2012.
India, according to the data, was third after Pakistan (471 incidents) and Iraq (194 incidents) in the incidence of IED blasts.