PATNA, India - A passenger train derailed in eastern India on Wednesday, killing four people, after a suspected explosion on the tracks during a protest called by Maoist insurgents, officials said.

Some 12 carriages of the Rajdhani Express, which was traveling from the capital New Delhi to the northeastern state of Assam, toppled over at around 2:00am (2030 GMT) in Bihar state's Saran district.

"Prima facie, it appears to be a case of sabotage," Railway Board chairman Arunendra Kumar told the Press Trust of India (PTI) news agency. "There was a blast on the track, which could have caused the derailment."

The chief spokesman of railways Anil Kumar Saxena said an expert team had rushed to the site to gather evidence.

"One of the possibilities could be sabotage by the Maoists," he told AFP.

Home Minister Rajnath Singh said it was "too early" to blame the insurgents, according to PTI, while a senior police officer said that a "technical fault" could have been to blame.

But Maoist rebels had earlier called for a day-long strike in the area to protest against the security forces and police said they had recovered three crude explosive devices that had been planted in a marketplace in a nearby town.

If confirmed as a Maoist attack, it would be the first by the insurgents since Prime Minister Narendra Modi's right-wing Bharatiya Janata Party came to power last month after a landslide election victory.

Separatist insurgencies affect large swathes of India's northeast, northwest and central regions, including the states of Chhattisgarh, Orissa, Bihar, Jharkhand and Maharashtra.

Many of the rebels say they are fighting authorities for land, jobs and other rights for poor tribal groups. The Maoist insurgency has cost thousands of lives.

SOURCE: AFP