The crude bombs that exploded in Patna and the nine explosives seized in Ranchi have strong similarities,investigators have found,indicating they were made by the same or a connected group of people.
Also,these two sets of pipe bombs and the cylinder bombs used in Bodhgaya earlier this year used the same Lotus brand watches as timers,with the Lotus watches in the Bodhgaya and Ranchi bombs belonging to the same Diamond series.
However,these bombs are unlike the ones used in the past by the Indian Mujahideen,which is suspected to be behind the two attacks in Bihar this year. This,sources said,could either mean that IM has found a new bomb-maker after the arrest of Yasin Bhatkal its co-founder and bomb expert or an entirely new group is behind the attacks.
After analysing the bombs used in Patna and those seized in Ranchi,Jharkhand Police suspect the IM is using a combination of two kinds of IEDs,both of which are new to the organisation.
They are using the high-intensity gelatin-based pipe bombs and flame-based elbow bombs that are relatively weak, said Additional Director General of Police S N Pradhan,spokesperson for the state police.
Investigators said this is a departure from the boat-shaped bombs and pressure cooker bombs used by IM in most attacks including in Delhi,Jaipur,Ahmedabad and Pune.
While the boat-shaped bomb originated in Bhatkal in Karnataka,pressure cooker bombs were first used by the Azamgarh module. After Yasin Bhatkal took over as the head of IMs India operations,boat-shaped bombs were more preferred and were used in the 2010 Bangalore blasts too.
National Investigation Agency sources said fugitive IM operatives Waqas and Tahseen Akhtar could be the groups new bomb-makers who are trying to change the shape of bombs. Waqas,said to be a Pakistani national,is a trained bomb maker.
Sources said the shape of the bombs seized from Ranchis Iram lodge was unlike any suspected to be used by the IM in the past.
The elbow bombs are weaker owing to their bent structure, ADG Pradhan said,adding that the IM seemed to be relying on elbow bombs as a backup option. Gelatin sticks are difficult to obtain,while materials used in an elbow bomb are easily available. There is no need to spend much time training individuals to make the latter either.
The police team also seized 25 gelatin sticks in Ranchi,which investigators say are supposed to go into iron pipes with brass caps on either side to make pipe bombs.
Describing the design of the bombs,a senior officer said the three elbows had been connected to make one bomb and was bound with adhesive tape.
Sources in Patna said the Patna and Ranchi pipe bombs were 8 inch x 4 inch,made of galvanised iron,used ammonium nitrate and were filled with iron nails to cause damage.
They have used very thick elbows,which will intensify the impact of the blasts. For this reason,there are no external shrapnel,the exploding pieces of pipe would serve that purpose, Pradhan said.
Sources also said the bombs used bulbs from decoration lamps as initiators and inflammable material extracted from matchsticks.
The bombs recovered in Ranchi apparently require almost no training to fabricate.
Imtiaz,during his interrogation,has mentioned a training CD. Apart from that,they seem to have had very little training from an instructor, said an officer.
Police now suspect that the pressure cooker containing a black powder,recovered from suspect Imtiaz Ansaris house,was used as a demonstration model. A report on the chemical composition of the powder says it comprised sodium nitrate,carbon and aluminium dust.
Elbow bombs are known to have been used by Maoists in Latehar district. They were also used in the April 15 Boston Marathon bombing.
Except for the fact that the IEDs we recovered had three elbows,almost everything about these two (sets of) devices is very similar. The explosive ingredients are almost the same. A manual timer is used in both cases, Pradhan said. – with inputs from Santosh Singh in Patna