GAUHATI, India - Police detained three people for questioning and are investigating whether local militants received help from other terrorist groups in carrying out coordinated attacks that killed at least 77 people in India's troubled northeast, officials said Saturday.
One of those detained overnight had a motorcycle license plate number that matched the one on a car used in Thursday's explosions in Gauhati, the capital of Assam state, a police officer said on condition of anonymity because he was not authorized to talk to reporters.
R. Chandranathan, an inspector-general of police, said a previously unknown group that claimed responsibility for the attacks has thanked its partners in a text message sent to local television station News Live.
The group, calling itself the Islamic Security Force (Indian Mujahadeen), also warned of future attacks, News Live said.
Chandranathan, who is heading the police investigation, said the group came into existence in 2000 mainly to thwart attacks by Bodo tribespeople on Muslim settlers in Assam state.
"Nothing has been heard of this group since then," he told The Associated Press.
Police were unaware of the group's activities and were trying to identity the partners mentioned in the message, he said.
The name echoes that of the Indian Mujahideen, a group unknown until May when it said it was behind bombings in the western city of Jaipur that killed 61 people. It also claimed responsibility for blasts in the western state of Gujarat in July that killed at least 45 and blasts in New Delhi in September that killed 21.
Bhaskar Jyoti Mahanta, the Assam state inspector general of police, said the state's largest separatist group, the United Liberation Front of Asom, or ULFA, was the main target of the investigation, but added that the sophistication of the blasts suggested the rebel group was "assisted by a force who has adequate expertise in such attacks." He did not elaborate.
In an e-mail sent to reporters, Anjan Borehaur, a ULFA spokesman, denied his group had any role in the blasts.
ULFA is one of the largest and most feared of several dozen militant groups active in the region, having launched dozens of attacks since it took up arms in 1979.
Most of the groups want independent homelands in India's northeast, an isolated region wedged between Bangladesh, Bhutan, China and Myanmar with only a thin corridor connecting it to the rest of India. Its residents are ethnically closer to Burma and China than India.
ULFA says Assam and the rest of the northeast were never traditionally part of India and that the federal government has been exploiting the area's natural resources while doing little for the indigenous people.
