Indian officials yesterday were looking for those responsible for a bomb that ripped through two cars of a passenger train in a remote area of eastern India on Monday, killing at least eight people and wounding about 60 others, officials and Indian media said.
Suspicion for the blast in West Bengal quickly fell on two groups: communist rebels active in wide swaths of rural India or militants fighting for an independent homeland in the neighboring state of Assam.
However, officials said police had no concrete leads.
A spokesman for Northeastern Railways, T. Rabha, said that the bomb had been planted in one of train's cars and the explosion occurred about 6:20pm near the Belacoba station, about 550km north of Calcutta.
The blast was so powerful it blew away the side and roof of one of the cars, the Press Trust of India (PTI) reported.
At least six passengers died at the scene and 53 others were wounded, Rabha said, adding that the death toll could rise because some of those injured were in serious condition.
PTI, citing railway police official Tushar Bhattacharya, later reported that the death toll had climbed to eight with about 60 wounded.
Witnesses said there was a flash followed by a deafening explosion. There were two small explosions immediately afterwards, PTI reported.
"Some of the passengers jumped out of the coach in panic, while many received burns," PTI quoted an unnamed witnesses as saying.
Prasad Ranjan Roy, home secretary of West Bengal, said it was not yet clear who was behind the attack.
"We have not yet been able to find a major clue to the blast but investigating teams would soon reach Belakoba, the blast site," Roy told PTI yesterday.
Earlier he said initial suspicion pointed to either Maoist rebels or Assamese militants, suggesting the blast could be the work of the relatively small Kamtapur Liberation Organization, an Assamese group tied to the larger United Liberation Front of Asom.
Although the Maoists are active in the area, they rarely attack civilians.
The Assamese separatists, in contrast, do target civilians and have intensified their attacks since the federal government ended a temporary six-week ceasefire on Sept. 24.
The insurgents have been fighting since 1979 for Assam's independence, saying India's central government -- 1,600km to the west -- exploits the northeast's rich natural resources while doing little to improve its poor infrastructure or to alleviate widespread unemployment.
Police said they have planted bombs in cities and towns.