Hundreds of thousands of people in Bangladesh and Myanmar have been evacuated as a cyclone bore down on
coastal areas home to flood-prone refugee camps for victims of sectarian unrest.
The United Nations has warned that more than eight million people could be at risk from Cyclone Mahasen, which is expected to make landfall in Bangladesh on Thursday.
Bangladesh evacuated more than 700,000 people living in low-lying areas to thousands of cyclone shelters on Wednesday, while Myanmar announced plans to relocate roughly 166,000 people on its northwest coast.
However, in Myanmar's state of Rakhine, many Muslim Rohingya made homeless by communal bloodshed last year said they were too scared to move, reflecting their deep mistrust of the authorities and of local Buddhists.
The UN office for the Co-ordination of Humanitarian Affairs (OCHA) said earlier that the cyclone appeared to have weakened.
It said in a written statement that Cyclone Mahasen had been downgraded to category one but the storm could still pose a risk to more than eight million people.
Mahasen is moving northeastwards over the Bay of Bengal and is expected to make landfall on Friday morning north of the Bangladeshi city of Chittagong, sparing Myanmar's restive Rakhine state from its full fury, the UN said.
The UN said about 8.2 million people in northeast India, Bangladesh and Myanmar would be affected, adding Bangladesh's Chittagong and Cox's Bazaar areas could face the worst of a tidal surge and heavy rains.
Cox's Bazaar, a long strip of coastline, is home to rickety camps housing many of the estimated 300,000 Rohingya Muslim refugees living in Bangladesh.
"Tropical Cyclone Mahasen is no longer expected to be as strong by the time it makes landfall, but that's not to say we should become complacent of this storm," said Al Jazeera's weather presenter Steff Gaulter.
"It will still deliver up to 500mm of rain, together with a storm surge and strong waves.
"Remember that this is a part of the world that has over 100,000 people living in tents, which offer precious little protection against the elements."
In Chittagong's export processing zone, all factories have been ordered closed as the cyclone approaches, Al Jazeera's Nicolas Haque reported.
Operations at the local airports in Chittagong and Cox Bazar's have also been suspended.
Local officials said 113 medical teams had been mobilised to deal with the impact of the cyclone and leave had been cancelled for all government employees.
Myanmar state media late on Tuesday said rescuers were searching for 58 missing Rohingya whose boat capsized after hitting rocks in a coastal waterway after they fled the cyclone's path to escape to higher ground.
"We've made all the preparations to face the cyclone," Mohammed Kamruzzaman, a government magistrate in charge of a Rohingya refugee camp in Cox's Bazaar, told the AFP news agency.
"We have been using loudspeakers to alert both documented and undocumented Rohingya refugees of the dangers of the cyclone.
"We've also stockpiled dry food, kept medical teams and ambulances on stand-by and shifted the sick and pregnant women from the camps to hospitals."
Experts say Bangladesh is better prepared to handle cyclones than authorities across the border in Rakhine, where tens of thousands of Rohingya made homeless by communal unrest last year languish in flood-prone camps.
A number of other Rohingya in Myanmar have expressed reluctance to relocate, reflecting deep mistrust of security forces following two outbreaks of violence last year that left hundreds of people dead and whole neighbourhoods razed.