KOLKATA (India) • A gun battle between supporters of India's ruling right-wing party and those of a regional rival has killed four people in West Bengal, police said yesterday, as violence raged in the tinderbox state.

At least 18 others were injured in the clashes that broke out last Saturday in the eastern state, which has been on edge since Indian Prime Minister Narendra Modi's Bharatiya Janata Party (BJP) launched an aggressive campaign to win parliamentary seats last year.

"Three of the dead were BJP workers while the other was a (regional) Trinamool party supporter," said a police official.

Local BJP leader Mukul Roy tweeted that three BJP workers were shot dead and a Trinamool minister said one of his party members was killed in the fight.

Violence peaked across the state during the general election that ran from April to May and has continued even after results were announced, with the BJP scoring a massive victory.

Both the BJP and Trinamool, led by the firebrand Modi critic Mamata Banerjee, accuse each other of killings, intimidation and corruption.

Sandeshkhali, the site of the latest gun battle, remained tense yesterday, with more than 100 police personnel standing guard in the area, witnesses said.

The clashes in Sandeshkhali broke out over the hoisting of BJP flags and the putting up of posters, said the BJP's general secretary in the state, Mr Sayantan Basu.

"They tried to throw away our party flags and posters and when we protested, our workers were shot from point-blank range," Mr Basu was quoted as saying by the Press Trust of India.

Local minister Jyotipriyo Mullick, who belongs to the Trinamool party, said one of its supporters was "hacked and shot dead by BJP workers".

State elections in West Bengal are scheduled to be held in 2021, with the BJP expected to give a tough fight again. The state has witnessed some of the most violent feuds between rival parties.

Mr Modi has called the killings "shameful and anti-democratic".

AGENCE FRANCE-PRESSE