It's hard to keep the insurgent groups straight in India's far eastern region: the United Liberation Front of Asom, the National Democratic Front of Bodoland, the Gorkha Tiger Force and many more.
But despite years of violence, no one had seen anything like the 13 coordinated bombs that killed 77 people and wounded hundreds in four towns Thursday — raising the possibility that better-armed, better-trained militants have joined the fray.
The groups are battling for power, for ethnic pride and for control of drug routes in India's northeast, an isolated collection of seven states and hundreds of ethnic groups and subgroups. They fight the government and each other in a region crippled by poverty and political chaos.
Many of the movements are small and poorly armed. A couple of the larger ones can assemble fairly well-armed assaults and bloody bombings. Over the past decade, violence has killed more than 10,000 people.
The United Liberation Front of Asom, which wants an independent state for the region's ethnic Assamese, is the largest of the northeast's myriad militant groups and the main suspect in Thursday's attack.
Few here, though, believe the group is capable of carrying out such a sophisticated attack on its own.
Bhaskar Jyoti Mahanta, head of the Assam state police, said the United Liberation Front of Asom was the main target of the investigation. But he added that the complexity suggested local rebels were “assisted by a force who has adequate expertise in such attacks.”
He did not elaborate, but Indian media and analysts were quick to accuse Islamic extremists — the most experienced of India's militants who have long been blamed for the country's bloodiest attacks.
“There's a very strong suspicion that it was jihadis” behind the Thursday bombings, said Noni Gopal Mahanta, head of the Peace and Conflict Studies Center at Gauhati University, in Assam's capital, Gauhati. “ULFA doesn't have the capacity to hit so many points with such magnitude.”
Islamic militants could have been drawn into an alliance with ULFA because a rival ethnic insurgent group, the National Democratic Front of Bodoland, has recently been targeting Muslim settlers in the northeast.
A local television station, News Live, said Thursday that it had received a text message from a previously unknown group claiming responsibility for the explosions. The group, calling itself the Islamic Security Force (Indian Mujahadeen), warned of future attacks.