The peripheral effect of the very severe cyclonic storm Mocha has started in the coastal regions of Chittagong and Barisal divisions, the Bangladesh Meteorological Department has said.

Cyclone Mocha is approaching the coastal areas of Bangladesh and Myanmar with a maximum wind speed of 210kmph, the BMD said in a special weather bulletin on Sunday.

According to the BMD, the cyclonic storm at midnight was centred about 490km south-southwest of Chittagong port, 410km south-southwest of Cox's Bazar port, 530km south of Mongla port and 460km south of Payra port.

The met office said Cyclone Mocha is likely to intensify further and move in a north-northwesterly direction and cross Cox's Bazar-north Myanmar's coast between 9am to 3pm.

The maximum sustained wind speed within 74km of the very severe cyclone centre at midnight was about 190kmph, rising to 210kmph in gusts.

The maritime port of Cox's Bazar was asked to hoist great danger signal No 10.

The maritime ports of Chittagong and Payra were told to hoist great danger signal No 8, while the maritime port of Mongla was advised to hoist local warning signal No 4.

The coastal district of Cox's Bazar and its offshore islands and chars will come under great danger signal No 10, the BMD said.

Meanwhile, the coastal districts of Chittagong, Feni, Noakhali, Lakshmipur, Chandpur, Barisal, Patuakhali, Jhalakathi, Pirojpur, Barguna, Bhola and their offshore islands and chars will come under great danger signal No 8.