Millions voted in the final phase of a marathon election in India's West Bengal on Thursday, despite a record-breaking spike in Covid-19 infections and deaths that has devastated the country.

Long queues of voters appeared outside polling booths as temperatures soared.

Many in rural parts of the state failed to observe social distancing rules, with some wearing masks but others hanging them loosely on their chins or from their ears.

Sporadic violence was reported from several constituencies, with crude bombs thrown and vehicles damaged.

Thousands have been killed in political violence in West Bengal over the decades, and this year's polls -- held in eight phases over the course of a month -- have also triggered deadly clashes between rival parties.

Winning power in the state of 90 million would be a major victory for Prime Minister Narendra Modi's Hindu-nationalist Bharatiya Janata Party, which is seeking to end a decade of rule by the state's firebrand leader Mamata Banerjee.

Nearly 8.5 million people are eligible to vote in the eighth phase of polling in the state. Results will be released on May 2.

"In line with the Covid-19 protocols, I call upon people to cast their vote and enrich the festival of democracy," Modi tweeted on Thursday.

India's West Bengal has held a marathon election over the past few weeks, against the backdrop of soaring virus cases and record deaths in the country
India's West Bengal has held a marathon election over the past few weeks, against the backdrop of soaring virus cases and record deaths in the country AFP / Diptendu DUTTA

Packed election rallies attended by mostly maskless crowds including in the restive eastern state, along with huge religious festivals, have been blamed for India's surge in cases over the past few weeks.

Before and since voting kicked off in late March, the Indian leader, along with Banerjee and other minor parties, held numerous rallies before cutting back as virus cases grew.

Major cities such as the capital New Delhi and financial hub Mumbai have borne the brunt of the recent surge, but infections are also rising fast in West Bengal and its capital Kolkata.

"One of the two persons undergoing RT-PCR tests in Kolkata and its suburbs is turning out to be positive," Kolkata Municipal Corporation's chief administrator, Firhad Hakim, told AFP.

"Hospitals are running out of beds. Bodies are also piling high at crematoriums," he said, adding that burial plots were running out and authorities were searching for new sites.

Just over 17,000 new infections were recorded by the state's health department on Wednesday, while almost 55,000 tests were carried out on the same day.

Nearly 30 million voters are also expected to take part in village elections on Thursday in India's most-populous state Uttar Pradesh, which has been badly hit by the virus.

India on Thursday added 379,257 cases and 3,645 deaths -- the highest since the start of the pandemic.

The world's second-most infected nation has recorded almost 18.4 million cases so far with nearly 205,000 dead.

Coronavirus