Around 200 cyclone centres have been set up across Bangladesh and thousands of residents in coastal areas evacuated following forecast of cyclone Mahasen hitting the country Thursday at 4 p.m.
Local TV channels reported that Mahasen was scheduled to hit Patuakhali and then move towards Chittagong or Cox's Bazaar, before making its way to Myanmar.
Authorities declared a level seven alert for cyclone Mahasen.
Airports at Chittagong and Cox Bazar have been shut down in the wake of the warning. Ports in low-lying coastal areas have also been closed.
In Patuakhali, 110 medical teams have been readied and several control rooms set up.
Across the state, schools have been converted to shelters in areas predicted to be affected most.
Higher secondary exams, scheduled to begin Thursday, have been postponed till May 25.