The Bangladesh Meteorological Department (BMD) has upgraded the maritime warning signal from No. 1 to No. 2 for the country's seaports as cyclonic storm Arnab intensifies over the Bay of Bengal.

According to a BMD bulletin issued today, Cyclone Arnab was centred over the east-central Bay and adjoining west-central Bay, near latitude 15.4oN and longitude 89.0oE.

The cyclone was located approximately 820 kilometres southwest of Chattogram, 745 kilometres southwest of Cox's Bazar, 785 kilometres south of Mongla and 745 kilometres south of Payra.

The storm is likely to move west-northwestward and intensify into a severe cyclonic storm over the west-central Bay by midnight on Monday, the bulletin said. 

It is then expected to move northwestward and cross the Andhra Pradesh coast of India by October 28 as a very severe cyclonic storm.

The maximum sustained wind speed within 54 kilometres of the cyclone's centre is around 62 kilometres per hour, with gusts or squalls reaching 88 kilometres per hour. The sea is expected to remain very rough near the cyclone's centre.

The BMD has advised all fishing boats and trawlers operating in the North Bay to remain close to the coast and proceed with caution until further notice.

Maritime operators have been urged to follow the latest weather updates and safety instructions as the cyclone continues to develop.