A powerful storm packing winds of up to 175 kph (109 mph) barrelled towards the coasts of eastern Bangladesh and Myanmar on Saturday, threatening around a million Rohingya refugees and others living in low-lying areas.
Thousands of people in both countries have already fled to safer areas ahead of the storm.
Cyclone Mocha is likely to intensify further and make landfall on Sunday between Cox's Bazar in Bangladesh and Myanmar, the Bangladesh Meteorological Department said in a bulletin.