Officials evacuated people from coastal belts and asked them not to go anywhere near the sea.

Tamil Nadu Chief Minister Jayalalithaa, who is supposed to visit Akkaraipettai fishing hamlet, has cancelled her visit at the last moment.

Thanjavur District Collector J Radkrishnan, who is overseeing the relief operations in the district, asked the residents of Akkaraipettai to evacuate immediately.

Latest TV reports said the Home Ministry has also issued a warning and asked people in hthe coastal areas to move.

TV pictures showed people leaving Nagapattinam in trucks and private vehicles.

Reports from Kochi in Kerala also said people were being shifted from the western part of Vypeen island to its eastern portion.

People from Vypeen, the most densly populated region in Asia, had been shifted to the mainland Ernakulam.

Most of them had returned to the island only two days back after spending sleepless nights at the relief camps.

District administrations has been asked not to allow people to remain within two km from the sea, Kereala CM Oommen Chandy said.

The initial information was given by the Defence Ministry and later confirmed by the Central Home Ministry.

The Centre has informed that there was a possibility of the state suffering a "shock" before noon on Thursday, the Chief Minister said.

He said the alert was being sounded in view of the advance information received and not to create panic.

As soon as the alert was sounded, police made announcement in coastal areas asking the people to remain vigilant.

The entire government machinery have been activated to meet any eventuality.

In many places people have begun to move away from the sea coasts in view of the alert.