Updated

A bomb tore through a moving train in India's remote northeast Thursday, killing five passengers and wounding four others, officials said. A little-known militant group claimed responsibility for the attack.

The New Delhi-bound high-speed Rajdhani Express had started from the eastern town of Dibrugarh in Assam state and had just crossed a station near Chungajan when the bomb exploded, said T. Rabha, an Indian Railway spokesman.

"A car near the luggage van took the whole impact of the blast before dawn Thursday. Five passengers were killed and four others wounded," Rabha told The Associated Press.

Dilip Beg, a leader of the Adivasi National Liberation Army (ANLA), said the group was behind the attack.

"Our fighters triggered the blast through remote control to force the government to grant special rights to our community," Beg told reporters by telephone.

Police did not immediately comment on the ANLA's claim of responsibility.

The Rajdhani Express is a popular air-conditioned train connecting India's northeast with the capital. It can carry 900 passengers, but wasn't running at full capacity Thursday, Rabha said.

The remaining 31 passengers in the affected car were shifted to another car and the train later resumed its journey.

Ethnic Adivasis, who make up the majority of the workers on tea plantations in Assam state, have been demanding that the government recognize them as a separate tribal group.

The Adivasis migrated to Assam more than 150 years ago from the eastern states of Bihar, Orissa, and Jharkhand and were employed by India's British colonial rulers to work in the state's tea plantations.

There are more than 800 tea estates in Assam, which produce almost half of India's nearly 1 million tons of tea a year.

Last month thousands of Adivasis had marched in the state capital of Gauhati. One protester was killed and more than 200 injured when the protests turned violent as marchers clashed with area residents.

Several rebel groups are fighting for autonomy or independence in the region. The militants say India's national government exploits the northeast's rich natural resources while doing little for the area's indigenous people.