Maritime ports of Chattogram, Cox's Bazar, Mongla and Payra have been advised to hoist distant cautionary signal one to alert vessels of a depression over the Bay of Bengal.

The weather office's advisory implies a low-pressure area is forming far at sea and surface wind could be up to 60 kmph.

In fact, the depression over the east-central Bay and the adjoining north-east Bay has moved slightly westwards and intensified into a deep depression over the same area, according to a Met office bulletin.

The depression was centred at 9am today about 480 kms south-southwest of Chattogram port, 415 kms south-southwest of Cox's Bazar port, 450 kms south of Mongla port and 405 kms south of Payra port, as per the bulletin.

It is likely to intensify further and move in a west/northwesterly direction, the Met office said.

Maximum sustained wind speed within 48 kms of the deep depression centre is about 50 kmph rising to 60 kmph. The sea will remain rough near the deep depression centre.

All fishing boats and trawlers have been advised to come closer to the coast and proceed with caution. They are advised not to venture into the deep sea.