Nearly 80 kg of deadly Research Development Explosive was used in the October 30 serial blasts in Guwahati alone, officials said on Monday as investigators worked on sketches of the suspects.

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

Terror stalks North East like never before

"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 were usually used to carry out a blast," said Padmapani, the Joint Director in the Forensic Science Laboratory in Guwahati.

Each of the cars was 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.

Assam: Bangladesh-based terror groups come under scanner

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.

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

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The sketches are being prepared 'in an organised manner under police supervision' and it would take some time to complete them, police said.

The police said that none of the earlier explosions were so well coordinated and intricately planned as none of the militant groups active in the state, including the United Liberation Front of Assam, has the expertise to make bombs of such high intensity.

North East turns into jihadi gateway 

They said perpetrators must have engaged local people to carry out the blasts as it would be difficult for outsiders to procure vehicles and plant the bombs at selected places.

Meanwhile, the Special Investigating Team under Inspector General of Police (Special Task Force) R Chandranathan has started investigations to ascertain the identity of the culprits and claimed to have received some vital leads in the case.

The threat in North East

The team, however, declined to disclose them at this stage as it could hamper further investigations.

Five persons have been arrested so far in connection with the blasts.

Chief Minister Tarun Gogoi had on Sunday said that Bangladesh and Pakistan based insurgent outfits were involved in the explosions.

Government spokesman Himanta Biswa Sarma had claimed on the day of the blast that jehadi elements with the help of
ULFA had carried out the serial attacks.