Veteran Indian politician Muthuvel Karunanidhi has died at the age of 94.
He was being treated for age-related illnesses in Chennai (formerly Madras) in southern India's Tamil Nadu state.
Mr Karunanidhi served as the chief minister of Tamil Nadu five times between 1969 and 2011, and also played a key role in federal politics. He contested - and won - 13 elections in the state, according to BBC report.
A school dropout, he made his name as a successful scriptwriter in Tamil films.
Police have increased security in Chennai amid fears of unrest among his supporters, who have gathered in the streets in large numbers.
Mr Karunanidhi died at 18:10 local time (12:40 GMT) on Tuesday, the Kauvery Hospital in Chennai said.
He was active in politics until his death and most recently contested the 2016 state assembly against his long-time opponent and bitter rival Jayaram Jayalalitha, who died later that year.
An atheist and self-declared rationalist, Mr Karunanidhi rose to political prominence in the 1940s as part of the Dravidian movement - which challenged the supremacy of upper caste Brahmins - and through his participation in anti-Hindi language agitations.