Sources in the investigating agencies say the forensics team is examining the use of fuel in the IEDs to trigger off the blasts. Earlier it was said that grease and wax were used to prepare the bombs, but now traces of fuel have been found, say sources.
Over the years ammonium nitrate has become a favourite among terror groups.
The sources, who are looking into this aspect of the case, say that it appears as though the bomb was assembled by a professional to create major damage. The investigators say they have managed to secure the evidence and none of it has been wiped out in the rains, and it is being examined in labs.
There are traces of ammonium nitrate and we are also looking into the possibility of RDX having been used in the bombs. Seven IEDs have been used and the bombs could have been triggered off by a timer device, the investigators add.
A forensics team from Hyderabad and New Delhi and the National Investigating Agency are working in tandem to gather more evidence regarding the explosives. Apart from this they are also looking into CCTV footage to find more clues regarding the terror attack.
