DMK Working President MK Stalin and son of ailing leader Kalaignar M Karunanidhi told cadre on Wednesday that his father was keeping well and warned them not to do anything extreme over the leader's health condition.

In a statement, Stalin expressed shock at learning the reported death of 21 DMK cadres who allegedly died following the hospitalisation of Kalaignar and expressed condolences to their family members.

Stalin urged the party members not to resort to activities that could lead to their deaths.

Citing the medical bulletin of Kauvery Hospital where the 94-year old veteran politician is admitted, Stalin said their leader's health was normalizing.

On July 31, the hospital said Karunanidhi would have to be remain hospitalised for an extended period owing to age-related health issues, including altered liver function.

Karunanidhi, who was Tamil Nadu's Chief Minister five times and who has never lost an election in the 13 times he has contested, was admitted to the Kauvery Hospital on July 28 following a drop in blood pressure.

"He was resuscitated and stabilized in the ICU (intensive care unit) and managed by a team of doctors and nurses," the statement said.

"There was a setback on his clinical condition on July 29 due to difficulty in breathing. He responded well to medical management and his vital signs are gradually normalizing," it said.

According to the hospital, Karunanidhi continues to maintain his vital signs with active medical support.

(With inputs from IANS)