At least 50 members of India’s security forces were killed yesterday when Maoist rebels ambushed a police outpost in the central state of Chhattisgarh in one of the deadliest attacks by insurgents in recent years.

Government officials said that between 300 and 400 separatists stormed the camp overnight, lobbing grenades and opening fire on its 80 occupants before escaping with guns and explosives.

Officials said that 50 policemen and tribal members recruited to a local militia died and 12 were injured, although the death toll could rise. Additional paramilitary forces were dispatched to the camp but their advance will be hampered by the dense forest that covers nearly 44 per cent of the state, providing effective cover for a growing number of separatist groups. The retreating rebels have also heavily mined the surrounding area.

The attack on the jungle outpost, in the village of Rani Bod-li, 500 km (310 miles) from Raipur, the capital, was the eighth big Maoist incident this year in Chhattisgarh, the worst-affected state. Tens of thousands have been displaced by left-wing rebels claiming to fight for the rights of oppressed tribes and landless workers.

The Maoists’ armed campaign began in India in 1967 but shows no signs of abating as Delhi refuses to negotiate with them.

Manmohan Singh, the Prime Minister, said last year that the insurgency — along what is described as a “red corridor” from the Nepal border in the northeast to Andhra Pradesh in the south — was the gravest threat to internal security since independence from British rule in 1947.

More than 9,000 armed rebels are estimated to operate in 15 of India’s 29 states. At least 372 people, including 154 civilians, were killed in Maoist-related violence across the country last year, according to the South Asia Terrorism Portal. The website is spearheaded by Kanwar Pal Singh Gill, security adviser to the Chhattisgarh government and the man credited with crushing the Sikh rebellion in Punjab in the early 1990s as director-general of police.

Central security resources were stepped up last year but state governments have been slow to implement them. Chhattisgarh claims to have 103 policemen for every 100,000 people, compared with a national average of 122. That is only half the ratio recommended by the United Nations.

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