Leftist rebels stormed a police camp in the troubled central Indian state of Chhattisgarh Thursday, killing 55 members of the police and tribal militia in one of the deadliest attacks by the insurgents in years.

Between 300 and 400 rebels attacked the camp surrounded by dense forest in the southern part of the state, throwing grenades and petrol bombs and setting fire to it before escaping with a cache of arms and explosives.

Chief Minister Raman Singh told the state legislature that among the dead were 16 policemen and 39 local tribal members recruited to a police militia.

The latest attack underlined the presence of leftist rebels in much of rural India where they have formed a "red corridor" stretching from the southern tip of India all along its southern, central and eastern forests and up to the border with Nepal.

Ajai Sahni, executive director at the New Delhi-based Institute for Conflict Management, said rebels have spent much of last year amassing an enormous cache of arms.

"This period has been a period of planning and of consolidation and you will now see the consequences," Sahni said, adding that mass support continued to grow across the "red corridor".

"You can expect a fairly abrupt escalation of violence over coming weeks and months," he added.

Last year, Prime Minister Manmohan Singh said the insurgency was the gravest threat to India's internal security since independence from British colonial rule in 1947.

More than 700 people were killed in the insurgency last year.

India's security forces and intelligence-gathering in the worst-affected states remain ineffectual in the face of the threat, Sahni said.

(China Daily via agencies March 16, 2007)