Indian security forces are battling Maoist rebels holding several villages in a remote part of eastern India.
State and federal troops are attempting to push their way into the insurgent stronghold of Lalgarh in West Bengal state, where villagers who support the Maoists are putting up resistance.
Indian Home Minister Palaniappan Chidambaram on Friday warned that efforts to retake the villages would "take some time," and urged the Maoists to talk with the government instead of fighting.
Thursday, police fired tear gas and rubber bullets to disperse sympathizers. Officials say troops are trying to avoid civilian casualties.
Indian authorities accuse the Maoists of killing at least five members of the region's ruling communist party (Communist Party of India-Marxist) earlier this week.
The Maoist rebels are part of a wider group of insurgents known as Naxalites who say they fight for the rights of the poor.
Many farmers in West Bengal have been angered by plans to build large industrial plants in rural areas. Tuesday, suspected Maoist rebels killed at least four policemen in a gunbattle in the neighboring state of Jharkhand.
The Naxalites are active in at least 13 of India's 29 states. Their decades-long insurgency has left thousands dead.