Police officials added that the casualty figure might surge as about 500 local police and Commando Battalion for Resolute Action (Cobra) personnel were still engaged in battling the heavily armed Maoists.

Maoists, who claim to be fighting for the rights of poor farmers and landless labourers, are expanding their influence in the rural areas of east, central and southern India.

Thousands have been killed in the Maoist insurgency that began in the late 1960s and which Prime Minister Manmohan Singh has described as one of the gravest threats to India's internal security.