DMK president M Karunanidhi continued to wage a grim battle for life tonight, with the five-time chief minister facing a "transient setback" while undergoing treatment at a hospital here where delirious supporters cried and prayed for the leader.

"It is true that there was a transient set back. But it has been set right due to intensive medical care. Do not believe in rumours. He continues to be treated at the ICU," DMK leader and former Union Minister A Raja told reporters at the hospital premises.

The announcement was greeted with loud cheers by the ardent admirers of Karunanidhi who have gathered in large numbers at the hospital.

Hundreds of policemen are deployed in and around the hospital in upscale Alwarpet.

A steady stream of DMK supporters visited the hospital since morning, but the crowd began swelling since 7:30 PM as news spread about the deterioration in his condition.

"There was a transient setback in the clinical condition of DMK president M Karunanidhi. With active medical support, his vital signs are normalising. He continues to be closely monitored and treated by the panel of expert doctors," a medical bulletin issued by Kauvery Hospital said at 9:50 PM.

Many party workers, especially women, were seen crying. They heaved a sigh of relief after the medical bulletin said he was breathing normally and his vital parameters had stabilised.

Karunanidhi was hospitalised in the wee hours yesterday after his blood pressure dropped. He had undergone a procedure at the Kauvery Hospital for replacement of a tracheostomy tube to help him breathe normally.