RDX, a lethal plastic explosive, may have bee used to trigger the three blasts in Dimapur on Saturday that killed at least 36 people and left over 100 injured even as the dominant Issac-Muivah group of the National Socialist Council of Nagaland (NSCN-IM) offered a reward of Rs 100,000 for anyone who is able to give information on the person or organisation responsible for the explosions.

"We have found traces of RDX at the blast site, although only a detailed investigation can establish it as a fact," a security official said.

Terming the blasts as a "satanic act", the NSCN(IM) has vowed to trace the culprits and punish them.

NSCN(IM), the powerful Naga underground group which has been in a ceasefire mode with the government since 1997, has a dominant presence in Dimapur. It, however, has a running battle going on with the other, less powerful faction called the NSCN(K).

Initially security agencies were veering towards the possibility that the NSCN(K) may have triggered the blasts to discredit its rival but as the day wore on and reports about large-scale violence unleashed by a banned outfit, the National Democratic Front of Boroland (NDFB) in neighbouring Assam came in, investigators now feel that NDFB may have been behind the blasts.

At least 25 people were killed in six different incidents in Assam.

Meanwhile, Nagaland Chief Minister Neiphiu Rio has ruled out the involvement of Naga undergrounds in Saturday's incidents.  Talking to the press after visting the two sites Rio said, "I don't see the hands of any Naga outfit in today's blasts as any such move would derail the present peace process they are involved with. This is a straight case of terrorist activity."   

He said a three-member panel comprising the Nagaland Commissioner, Home Commissioner and IGP (Intelligence) has been formed to probe into the blast.

The probe report will be submitted within 10 days.

At the Dimapur railway station and two markets presented a gory sight with torn limbs and splattered blood.

"Many of the injured have come with multiple wounds in their faces and abdomen," a doctor in Dimapur, said.

Some of them are in a state of shock and absolute trauma. "We are trying our best to cope with the situation although we have never come across this kind of an emergency situation of such a magnitude," he added.