Maoist bus attack kills about 35 in India, government says

RAIPUR, India (Reuters) - About 35 people, including policemen, were killed when Maoist rebels detonated a land mine under a bus in central India on Monday, a government official said, the second major attack in as many months.

The attack in the mineral-rich state of Chhattisgarh was the worst since a strike by Maoists in the same region in April which killed at least 75 policemen. Home Minister Palaniappan Chidambaram said it may trigger a change in the government's strategy against the Maoists in some states.

"We have suffered some major setbacks. We need to revisit tactical operations in Chhattisgarh and Orissa (states). These are the flashpoints," he told NDTV news channel.

The chief ministers of several states racked by Maoist violence had asked for military support, he said.

The attack occurred in Dantewada district of Chhattisgarh, said to be the worst hit by four decades of an insurgency that has killed thousands of people and has been described by the government as India's gravest internal security threat.

"The bus was tossed 20 feet into the air and when it fell it created a 10-foot crater," a Chhattisgarh police official said on condition of anonymity.

There were 55 people on the bus. Most of the victims were civilians, federal Home Secretary Gopal Pillai said in New Delhi.

The rebels have stepped up attacks in response to a government offensive. Police say recent attacks are an act of desperation, but the strikes have also raised questions about how well prepared security forces are to tackle the Maoists.

The Maoists control large but poor areas of the region and often attack railway lines and mining operations to cripple economic activity, such as the transportation of coal to power and steel companies.

The attacks also signal India does not fully control its territory, adding to the risk of investing in states such as Jharkhand, Andhra Pradesh and Orissa, where the rebels are strong and where some of the biggest foreign investments are planned.

The effect of the Maoist insurgency has already taken its toll on business. Work on a $7 billion steel plant in West Bengal state by India's third-largest steel producer, JSW Steel Ltd, has been delayed over security concerns.

The rebel movement started as a peasant revolt in Naxalbari village in West Bengal in 1967. The rebels say they are fighting for the rights of the poor and the disenfranchised.

(Additional reporting by Bappa Majumdar; Writing by Krittivas Mukherjee; Editing by Rina Chandran and Paul Tait)