As many as 11 police officers and four Maoist fighters have been killed in a nine-hour shootout at a mine in eastern India, according to police.
Dozens of armed Maoist fighters stormed a bauxite mine in the Panchpatmali area of Orissa on Sunday and held about 100 miners hostage before police regained control on Monday, officials said.
None of the workers held inside the mine were harmed, said the director of the National Aluminum Company (Nalco), the state-owned mine company targeted in the attack.
The Maoists have stepped up attacks in eastern and central India in advance of the country's general election in April and May, which they are boycotting.
MM Praharaj, a senior police official, said the attackers were planning to steal large quantities of explosives used for mining, but fled without them when more police reached the area.
Praharaj said the fighters were probably trying to disrupt the upcoming national election, due to start on Thursday.
"We are trying our best to ensure that the polls are conducted peacefully,'' he said.
The Maoists, who say they are fighting for the rights of poor farmers and landless labourers, have threatened to chop off the hands of voters if they go to polling booths.
Nalco is one of India's largest aluminium exporters and the Panchpatmali mines are the company's main sources of bauxite, the primary ingredient in aluminium.
The company said the open pit mine, with a deposit of more than 310 million tonnes of bauxite reserves, would be closed for at least a day as a result of the attack.