Chennai, Apr 29 (IANS): Cyclonic storm Fani over southeast Bay of Bengal is very likely to intensify into a severe cyclonic storm during next six hours and into a very severe cyclonic storm during subsequent 24 hours as it moves towards India's eastern coast, the IMD said on Monday.

Fani moved north-northwestwards with a speed of about 18 kmph in last six hours and lay centred at about 810 km east-southeast of Chennai and 950 km south-southeast of Machilipatnam (Andhra Pradesh), the Indian Meteorological Department (IMD) said.

It is very likely to move northwestwards till May 1 and thereafter recurve north-northeastwards towards the Odisha coast.

Fishermen along the Puducherry, Tamil Nadu and south Andhra Pradesh coasts are advised to venture into the sea only till May 1, those on the north Andhra Pradesh coast during May 1-3 and those of Odisha and West Bengal coasts from May 2 onwards.

Those who are out in deep sea in the above areas have been advised to return to the coasts.