W Bengal is the most important with the BJP pushing hard to win power in the largely Bengali-speaking region for the first time
One person was killed, and bombs were thrown at a polling station on Saturday as India's hotbed of political violence West Bengal held elections, with Prime Minister Narendra Modi seeking to unseat one of his fiercest opponents.
Victory in the eastern region of 90 million would be a major achievement for Modi's Hindu nationalist Bhartiya Janata Party as it looks to expand further its power base beyond its Hindi-speaking northern heartlands.
In a state where thousands have died since the 1960s, fresh incidents of violence were reported Saturday with police saying a mob threw bombs at one polling station, seriously injuring an officer.
The president of the BJP in the state, Dilip Ghosh, said one of their supporters was killed by members of the region's ruling Trinamool Congress party in the early hours.
"His body was found in the compound of his mud hut," he said.
Assailants also attacked the vehicles of at least two election candidates, police said.
Bank employee Bablu Das, 32, said voting was taking place in his district in the west of the state "in an atmosphere of violence" and that many people were too scared to vote.
Because of extra security the election is being held over eight phases concluding on April 29.
The campaign has seen huge rallies despite a sharp rise in coronavirus cases in India in recent weeks, including around 800,000 people attending one Modi event in Kolkata.
The north-eastern state of Assam also went to the polls on Saturday in the first of three phases, while Tamil Nadu, Kerala and Puducherry vote on April 6. Results from all are due on May 2.
Challenge from 'Didi'
West Bengal is the most important with the BJP pushing hard to win power in the largely Bengali-speaking region for the first time.
But the party faces a tough opponent in incumbent chief minister Mamata Banerjee, 66, a firebrand nicknamed "Didi,” and her Trinamool Congress party.
Activists from both parties have been shot and hacked to death, their bodies sometimes hung from trees. Crude bombs, available on the black market for as little as $1.40, have been used to kill, maim or intimidate voters.
The mutilated body of one BJP activist, Sukhdev Pramanik, was found face-down in a pond in the village of Chandpara in December.
Sumita, the mother of Shoubhik Dolai, a Trinamool activist killed last month, told AFP that "they pumped bullets into him... I got to know when I saw the news on TV."
Arati Jerath, a political analyst, said Banerjee has been at the forefront of trying to form an "anti-Modi opposition front."
"Conquering her would put an end to that kind of challenge," she told AFP.
In Assam, the BJP leads an alliance and is hopeful of retaining power against a strong coalition of Congress and smaller regional parties.
The state, home to 32 million people, is polarised along ethnic and religious lines, with immigration from neighbouring Bangladesh one of the biggest campaign issues.
A "citizenship list" in Assam state in 2019 left off almost two million people unable to prove they were Indian, many of them Muslims, a process many fear the BJP wants to roll out nationwide.
Home minister Amit Shah, Modi's close ally, told a rally in Assam on Friday that the BJP would bring laws against "love jihad" and "land jihad," referring to Muslim men luring Hindu women into marriage and conversion, and Muslims stealing land.
Several BJP-run states have introduced laws against "love jihad" although it is an overwhelmingly fictitious phenomenon, with many among India's 200 million Muslims seeing it as Modi's latest assault on their minority community.