Once an area is cleared, the plan also calls for introducing development projects such as roads, bridges and schools in hopes of winning support of the tribal people. Also known as adivasis, they have faced decades of exploitation from local officials, moneylenders and private contractors, numerous government reports have found.

“The adivasis are the group least incorporated into India’s political economy,” said Ashutosh Varshney, an India specialist at Brown University, calling their plight one of the “unfinished quests of Indian democracy.”

Image Indian officers patrolled a forest around their base in Barsur, right on the edge of rebel-controlled territory in Chattisgarh. Credit... Keith Bedford for The New York Times

The Maoist movement first coalesced after a violent 1967 uprising by local Communists over a land dispute in a West Bengal village known as Naxalbari, hence the name Naxalites.

Some Communists would enter the political system; today, the Communist Party of India (Marxist) is an influential political force that holds power in West Bengal. But others went underground, and by the 1980s, many found sanctuary in Chattisgarh, especially in the region across from the Indravati River known as Abhujmad. From here, the Maoists recruited and trained disgruntled tribal villagers and slowly spread out. For years, the central government regarded them as mostly a nuisance. But in 2004, the movement radicalized, authorities say, when its two dominant wings merged with the more violent Communist Party of India (Maoist).

Authorities in Chattisgarh then deputized and armed civilian posses, which have been accused by human rights groups of terrorizing innocent villagers and committing atrocities of their own in the name of hunting Maoists. Now, violence is frequent, if unpredictable, like the ambush near the village of Laheri, in Maharashtra State, carried out by the Maoists on Oct. 8.

That morning, following a tip, a police patrol chased two Maoist fighters and stumbled into a trap. Two hundred Maoists with rifles and machine guns lay waiting and opened fire when the officers came into an exposed area of rice paddies. Seventeen officers died, fighting for hours until they ran out of ammunition.