Bangladesh, Oct. 23 -- The Met Office on Friday advised maritime ports to hoist local cautionary signal number 4 and warned that low-lying coastal areas could be inundated by tidal surges.

In a special bulletin in the morning, the Met Office said a deep depression has formed in the Bay of Bengal. It was located in the northwest Bay and adjoining area and moved northeastwards over the same area.

At 6am, it was centred about 445km west-southwest of Chittagong Port, 445km west-southwest of Cox's Bazar Port, 240km southwest of Mongla Port and 280km southwest of Payra Port.

It is likely to move in a northeasterly direction, the weather office said.

The maximum sustained wind speed within 48km of the deep depression centre is about 50kph ri...