At least five people were killed in India's eastern state of West Bengal on Sunday when rival parties contesting a local election clashed with bombs and guns, police said.

The village council elections are seen as a crucial indicator of grassroots support of the Communist Party of India-Marxist (CPI-M), which runs the state, after a year of often violent protests by villagers over the local government's seizure of their land for industry.

The Marxists have also fallen out with their partners in the state's coalition government the over its pro-industry stance.

Sunday's clashes were mostly between supporters of the CPI-M and opposition Congress party which are partners in the ruling national coalition in New Delhi but rivals in West Bengal.

Local news channels ran footage of burning thatched homes and bullet-ridden bodies lying in villages in Murshidabad district, about 350 km (220 miles) from Kolkata, the metropolis previously called Calcutta.

Women and children were seen wailing and running in panic as men tried to douse the flames.

"The clashes occurred in Domkol and Raninagar areas of Murshidabad district," police Inspector General Raj Kanojia said, confirming five deaths.

But television reports and the Congress party put the death toll at 10.

"The CPI-M unleashed state-sponsored terror in the districts to capture booths and win polls," Congress leader Subrata Mukherjee told Reuters. "The communists can see their days numbered and so they are desperate."

At least seven people had been killed in the previous two rounds of voting. The votes will be counted on May 21.