Indian Hindu nationalist politician Bal Thackeray, who founded the right-wing Hindu party Shiv Sena, has died after suffering a cardiac arrest, according to his doctor.
Jalil Parkar told a huge crowd assembled outside Thackeray's house in India's financial hub of Mumbai on Saturday that the veteran politician had "breathed his last".
The 86-year-old Thackeray, regarded as one of India's most divisive politicians, had been placed on a ventilator earlier after his health deteriorated sharply, and Parkar said attempts to revive him had failed.
Shiv Sena party became synonymous with deadly communal violence during its campaign to protect local Marathi-speaking people and their culture from migrant workers.
Police stepped up security near Thackeray's residence in anticipation of violence from supporters who sobbed into their handkerchiefs outside his home.
"He was an iron man, he spoke in the language of the masses. It worked very well because he connected with them at the very basic level. He gave them hope," Shobhaa De, novelist and a popular columnist, told India's CNN-IBN network.
Thackeray's funeral rites were due to be held on Sunday.
A massive procession was planned through the streets of Mumbai for Thackeray, nicknamed The Tiger because of his fearlessness and readiness to take on any opponent.
Shiv Sena, which has controlled Mumbai's city council since the mid-1990s, is a staunch ally of the Hindu nationalist and main opposition Bharatiya Janata Party.
The BJP announced it was cancelling its attendance at a dinner to be held by Manmohan Singh, India's prime minister, on Saturday night to show respect for Thackeray.
A stream of politicians, cutting across party lines, and top Bollywood entertainment figures had visited Thackeray's house in the past few days.
Thackeray's son Uddhav, the Shiv Sena executive president, earlier in the week had appealed to the party's supporters to stay calm.