Earlier this week, a large group of armed rebels entered the Lalgarh region, a heavily forested part of West Bengal, and seized control of many villages. They are believed to have killed at least five members of the Communist Party of India (Marxist), which rules the state.
The rebels, also known as Naxalites after Naxalbari, a village in West Bengal where the movement originated in 1967, say they are insipred by Mao Zedong, China's revolutionary leader.
West Bengal's government has vowed to regain control of the region.
"We can't go for a crackdown right away, as Maoists will use tribal women and children as human shields." Buddhadeb Bhattacharjee, the state's chief minister said. "We have to minimise casualties."
The Naxalites have fought for several decades across India, demanding land and jobs for the poor. They have urged the government not to try to retake the Lalgarh region, warning that local support was on the side of the rebels.