NEW DELHI (AFP) - At least 100,000 villagers in eastern India have been forced to flee their homes in spiralling violence spurred by a state-backed anti-Maoist vigilante group, a US-based rights group said Tuesday. Human Rights Watch accused government forces of taking part in some of the violence, in which vigilantes allegedly attacked and killed supporters of banned left-wing rebels in the Maoist heartland of Chhattisgarh state. The rights group is calling for the state government to immediately end its support of the vigilantes and investigate rights abuses by its forces, as well as protect villagers who want to return home. "It is 100 per cent certain that government forces were involved," said Jo Becker, director of children's advocacy at Human Rights Watch, ahead of the group's release on Tuesday of a report on rights abuses in the state. "We literally talked to dozens of eye-witnesses. In numerous cases they were very clear that government forces were present and not only present, they were actively participating," added Becker, who was part of a research team the group sent to the state in 2007 and 2008. One man told how police came to his village in 2006 by helicopter and burnt down huts. "Police came in three helicopters, landed there and set huts on fire," the unnamed man was quoted in the report as saying, adding that more huts were burned by police as recently as October 2007. The Chhattisgarh government has praised - but denies backing - the Salwa Judum movement, which began village-to-village rallies in 2005 aimed at rooting out the left-wing rebels. Prime Minister Manmohan Singh has described the Maoists, who say they are fighting to improve the lot of India's rural poor, as the biggest threat to India's internal security. Many villagers in the state have told rights groups and journalists they participated in the anti-Maoist rallies under duress from local political leaders. More than half of the 837 deaths due to Maoist-related violence in India last year took place in Chhattisgarh, according to India's home ministry. And both sides have put children on the frontlines of hostilities, the report said. "The state government does need to accept responsibility for creating this situation. People are caught between the naxals (rebels) on the one hand and government and the Salwa Judum on the other," said Becker. "State support for Salwa Judum has created both a human rights and a humanitarian crisis. You have a 100,000 people who are displaced and living in desperate conditions." Amid what became a small-scale civil war, large numbers of villagers fled their homes, with close to 50,000 people now living in government-run relief camps with little hope of returning home. Another 30,000 to 50,000 villagers have fled to the forests of neighbouring Andhra Pradesh state. "The abuses started over three years ago. No one can claim any longer they're not aware of the crisis that exists in Chhattisgarh," said Becker. "There's no excuse not to act."