SARDIHA, India - Rescuers scoured the wreckage of a passenger express train Friday that derailed and collided with a cargo train in eastern India, killing at least 71 people and injuring nearly 200. The government accused Maoist rebels of sabotaging the tracks.

As night fell, railway workers and paramilitary soldiers were using two cranes to lift and pry apart train cars in search of survivors from the Jnaneswari Express, which was heading from Calcutta to suburban Mumbai when it derailed about 1:30 a.m. Friday.

Railway officials said they expected the death toll to rise because bodies were still trapped between the engines of the two trains, which collided along a rural stretch of track near the town of Sardiha, about 90 miles west of Calcutta in West Bengal state.

The area is a stronghold of India's Maoist rebels, known as Naxalites, who had called for a four-day general strike in the area starting Friday. The Naxalites have launched repeated and often-audacious attacks in recent months - despite the government's assertions that it was conducting its own crackdown.

Just days ago, the rebels ambushed a bus in central India, killing 31 police officers and civilians. A few weeks before that, 76 soldiers were killed in a rebel ambush - the deadliest attack by the rebels against government forces in the 43-year insurgency. There also have been dozens of smaller attacks.

The government vowed again Friday to crush the Naxalites. "The Maoists have done this work," West Bengal Chief Minister Buddhadeb Bhattacharjee said in Calcutta. "All-out efforts will be made to free the state and the country from this danger."

Analysts say the government is hobbled by vacillating policies, poorly trained and ill-armed security forces, and vast tracts of India where the government has little influence and where poverty has brought considerable support to the Naxalites.

The rebels, who have tapped into the poor's anger at being left out of India's economic gains, are now present in 20 of the nation's 28 states and have 10,000 to 20,000 fighters, according to the Home Ministry.

"There is an absence of government, there is an absence of competence in government, there is an absence of coherence in response," said Ajai Sahni, a New Delhi analyst with close ties to India's security establishment. "The purpose of the Maoists is not to resolve grievances but to harvest them, and there are numerous grievances in the country to harvest."

In Sardiha, officials said the train tracks had been sabotaged but disagreed about exactly what had happened. Some said there was an explosion; others blamed cut rail lines.

Bhupinder Singh, the top police official in West Bengal, said posters from the People's Committee Against Police Atrocities, a group local officials believe is closely tied to the Maoists, had been found at the scene taking responsibility for the attack.

But a spokesman for the group, Asit Mahato, denied any role, the Press Trust of India news agency reported. The Maoists seldom claim responsibility for their attacks.