Security forces in India's West Bengal say they are on "high alert" as Maoists began a four-day protest against a security operation in which eight of their fighters were killed.
The rebels, including three women, were killed by security forces in West Midnapore district on Wednesday.
The police say they are expecting rebels attacks over the weekend.
Authorities have been under pressure following a wave of Maoist-led violence in recent months.
In late May, more than 145 people were killed when a train crashed in West Bengal after Maoist rebels allegedly sabotaged the rails.
West Bengal police chief Bhupinder Singh told the BBC that police and paramilitary federal forces in the affected areas have been put on "red alert".
"We anticipate retaliatory attacks and explosions by the rebels over the weekend," he said.
Earlier Maoist leader Comrade Khokan had said that the rebels would observe a two-day protest over the weekend.
Later, he said the protest would continue until Monday in the Junglemahal area - a Maoist stronghold - in West Midnapore.
A local rebel militia has also called for a separate strike in the area on Friday in protest against "police atrocities on innocent villagers".
A militia spokesman said a deaf and mute tribal boy had been arrested by the police and described as a Maoist rebel.
"A physically handicapped boy has been framed by the police," a spokesman of the militia said.
Early on Wednesday, eight rebels were killed during a six-hour-long firefight in the Rajna forests near the troubled Lalgarh enclave.
Their bodies were recovered along with some guns and ammunition which had been earlier looted from a police armoury, police said.
Thousands have died in the rebels' decades-long fight against the state.
Maoist rebels have in recent months stepped up attacks in response to a government push to flush them out of their jungle bases.
Indian forces launched the offensive in what is known as the "red corridor" - a broad swathe of territory in eastern and central India where the Maoist rebellion has been gathering strength.
Nearly 50,000 federal paramilitary troops and tens of thousands of policemen are taking part in the operation in several states.
In April, 76 paramilitary troops were killed in an ambush - the single deadliest attack on the Indian security forces by the rebels.
Prime Minister Manmohan Singh has described the Maoist insurgency as India's biggest internal security challenge.