Forensic officials claimed that nearly 80 kg of RDX was used in the three Maruti cars planted at the three blast sites in Guwahati. The blasts that took place in several parts of the state claimed over 80 lives.

"Such large quantity of RDX were never used to carry out explosions in Assam before as Ammonium Nitrate, with plasticers as propellants and Programmable Time Devices (PTD) were usually used to carry out a blast," said Padmapani, the Joint Director in the Forensic Science Laboratory in Guwahati.

Each of the cars were laden with 25 to 30 kgs of RDX to carry out the blasts and a total of 75 to 80 kgs was used to cause maximum damage, he said.

The officials said a maximum amount of explosives used for a single blast in the state was 10 kg at Dhemaji during the 2004 Independence Day which killed 13 people, including 10 school children.

Police have asked a Kolkata-based artist to prepare sketches of suspects involved in the blasts based on the eye-witnesses accounts.