Dhaka: Cyclone Amphan has killed at least 12 people in seven coastal districts of Bangladesh before turning into a land depression, authorities said on Thursday.

The cyclone is likely to move further in a north-northeasterly direction and weaken gradually, bdnews24 quoted the Bangladesh Meteorological Department as saying in its latest update.

Patuakhali, Satkhira, Pirojpur, Bhola and Barguna are among the seven districts where casualties were reported.

The Met Office instructed the maritime ports to lower great danger signals and hoist local cautionary signal No. 3 instead, said Shamsuddin Ahmed, Director of the weather office.

On Wednesday, the maritime ports of Mongla and Payra were advised to keep following great danger signal No. 10, while Chattogram and Cox's Bazar ports were advised to continue hoisting great danger signal No. 9, as Amphan approached the coast.

The low lying areas of the coastal districts and their offshore islands and chars were inundated by storm surges of 10-15 feet above the normal astronomical tide.