Senior Tamil politician M. Karunanidhi, the 94-year-old leader of the Dravida Munnetra Kazhagam (DMK), is said to be in a stable condition after a health scare, as the state of Tamil Nadu prayed for his recovery.

Tamil Nadu Chief Minister Edappadi K Palaniswami met him yesterday and told Indian media that the much-respected leader is feeling better and recovering well.

Mr Karunanidhi was admitted to Chennai's Kauvery Hospital on Saturday after a drop in his blood pressure. Doctors have said he is also suffering from a urinary tract infection.

The size of the crowd gathered outside the hospital has grown, with an estimated 25,000-plus people present. Police have put up barricades and urged emotional supporters not to resort to violence.

"He is better, he is better," Ms M. Kanimozhi - Mr Karunanidhi's daughter - told Indian media as she was leaving the hospital.

Mr M. K. Stalin, who is seen as Mr Karunanidhi's successor, appealed to supporters to maintain calm.

On Sunday evening, the hospital said there had been a "transient setback in the clinical condition of Kalaignar".

Mr Karunanidhi is popularly known as Kalaignar, which means artist or poet and is a reference to his past as a film screenwriter and author of other scholarly works.

"With active medical support, his vital signs are normalising," the medical bulletin said. "He continues to be closely monitored and treated by the panel of expert doctors."

The party patriarch, who is always seen in public wearing his trademark dark glasses, has not made any public appearances for over a year.

A powerful orator, Mr Karunanidhi has dominated Tamil Nadu politics for decades, shaping the DMK and acting as one of the key drivers of the state's Dravidian movement, which espouses rationalism and atheism.

He has been elected to the Tamil Nadu Legislative Assembly 13 times from 1957 to 2016 and is a five-time chief minister. He has been party president for half a century and also made an impact on federal politics through strategic tie-ups with the two main national parties, the Congress and Bharatiya Janata Party, on separate occasions.

Leaders across the political spectrum have visited him or sent their good wishes. India's Vice-President Venkaiah Naidu visited him in hospital on Saturday while Prime Minister Narendra Modi wished him a speedy recovery.

"Enquired about the health of Kalaignar Karunanidhi Ji and offered any assistance required," Mr Modi tweeted last week.