Investigation into the blast at a court complex in Mysuru has revealed that the explosive material in the IED was wrapped in sheets of a Malayalam and an English newspaper. Pieces of the newspapers are among evidence recovered from the crime scene by police and NIA forensic experts.
Following inspection of the crime scene, investigators also feel that there are striking similarities between the blast at Mysuru and blasts on court premises in Kollam in Kerala on June 15 and Chittoor in Andhra Pradesh on April 7.
It has been found that printed circuit boards were used as timers in IEDs planted at the Kollam court and the Mysuru court. The boards used in both blasts are of the same make, sources said.
The IEDs used in all three blasts were found to have been powered by an array of 9V batteries strapped around metal containers that were packed with explosive material like potassium chlorate and gunpowder.
In Chittoor, cases of 14 batteries were found in the debris. In Kollam, 18 batteries were found to have been used and in Mysuru, cases of 12 batteries were found.
Experts feel that the line of batteries was used to ensure that electrical charge transferred to bulb filaments used as detonators is maximised. Sources said the IEDs used in the three blasts showed that someone with a degree of expertise is at work.
Probe into Chittoor and Kollam blasts have hinted at possible involvement of remnants of the proscribed Al Ummah outfit. In a letter sent to a commercial tax office in Chittoor after the blast, a group called “Base Movement’’ had claimed responsibility for the blast. Base Movement is suspected to be a new name assumed by former members of Al Ummah and a few regional groups who now swear allegiance to Al Qaeda.
Given the inter-state implications of Mysuru blast, the Karnataka government is expected to hand over investigation into the case to the NIA in the coming days.
Meanwhile, pieces of newspapers found from the Mysuru blast site are yet to be analysed. From preliminary analysis, they have been found to be a few months old, sources said.
Newspapers used to wrap IEDs have proven to be leads for investigators in the past. In April 2010, following a blast at Chinnaswamy stadium ahead of an IPL match, police had found two unexploded IEDs near the stadium. The IEDs were found wrapped in sheets from the Tumkur edition of Kannada newspaper Prajavani.
Police had launched a massive search covering newspaper vendors and subscribers in Tumkur. Although the search did not yield results then, arrest of several members of Indian Mujahideen later revealed that IM executed the blast while using Tumkur as a base.