It was a Category 1 cyclone - the weakest level. It could hit land with maximum wind speeds of about 120 kph, said Mohammad Shah Alam, director of the Bangladesh Meteorological Department. Bangladesh's private Independent TV reported Thursday that high winds had already flattened about 100 mainly mud-and-straw huts in Patuakhali district south of Dhaka, the capital.
Heavy rain and storm surge could prove deadlier than the wind. Bangladesh's meteorological office said the cyclone was moving so slowly it may take a whole day for it to pass the Bangladesh coast.
In Myanmar's Rakhine state, around 140,000 people - mostly Rohingya - have been living in crowded camps since last year, when two outbreaks of sectarian violence between the Muslim minority and ethnic Rakhine Buddhists forced many Rohingya from their homes.
Nearly half the displaced live in coastal areas considered highly vulnerable to storm surges and flooding from Cyclone Mahasen, which is expected to make landfall early Friday.
"Pack and leave," a Rakhine state official, U Hla Maung, warned as he walked through a camp near Sittwe, the state capital. Accompanied by more than a dozen soldiers and riot police, he suggested that people living there move to a nearby railroad embankment, then left without offering help.
Distrust of authorities led many Rohingya to stay where they were Thursday morning.
"We have no safe place to move, so we're staying here, whether the storm comes or not," said Ko Hla Maung, an unemployed fisherman. "... The soldiers want to take us to a village closer to the sea, and we're not going to do that. ... If the storm is coming, then that village will be destroyed."
Kyaung Wa, a cycle-rickshaw driver who has spent nearly a year in area camps after his house was destroyed in the violence, also was among the thousands who would not leave. If his current home is little more than a hut covered with a plastic sheet, he fears ending up someplace even worse, and living deeper in the countryside and away from work.
Officials, he said Wednesday, had been trying to empty his camp for months.
"Now they say, 'You have to move because of the storm,'" he said. "We keep refusing to go. ... If they point guns at us, only then will we move."
President's Office Minister Aung Min told reporters Wednesday that the government guarantees the safety of the Rohingyas during relocation and promises to return them to their current settlement when the storm has passed.
Heavy and moderate rain and gusty winds were lashing the Bangladesh coast Thursday morning. River ferries and boats were suspended, and scores of factories near the choppy Bay of Bengal were closed.
Cox's Bazar, a seafront town in Bangladesh in the expected path of the cyclone, had rain, wind and higher than normal tides. There was flooding in low-lying areas of several nearby island towns, said Ruhul Amin, a government official. Tens of thousands of people have left shanty-like homes along the coast for cyclone shelters in schools, government buildings and about 300 hotels.
Amin's three-story office building was turned into a shelter for about 400 men, women and children, many of them taking their livestock with them.
Huddling with the crowd, Mohammad Tayebullah said, "Each time there is a cyclone warning we come to the town for shelter. This has become part of our life."
Related heavy rains and flooding in Sri Lanka were blamed for eight deaths earlier this week, said Sarath Lal Kumara, spokesman for Sri Lanka's disaster management center.
In Myanmar at least eight people - and possibly many more - were killed as they fled the cyclone Monday night, when overcrowded boats carrying more than 100 Rohingya capsized. Only 42 people had been rescued by Wednesday, and more than 50 Rohingya were still missing, said Deputy Information Minister Ye Htut.
Much attention was focused on western Myanmar because of fears over the fate of the crowded, low-lying Rohingya camps.
Myanmar's government had planned to move 38,000 people within Rakhine state by Tuesday but "it is unclear how many people have been relocated," the UN office said, adding that Muslim leaders in the country have called on people to cooperate with the government's evacuation.
With sprawling camps still crowded with people, it appeared very few Rohingya had agreed to leave, despite offers of additional food rations.
The ones that had left said they had little choice.
"They just put us on the truck and brought us here," said Mahmoud Issac, a day labourer now living with his family and about 500 other Rohingya on the grounds of a small mosque. His wife and five children live on the ground floor of a two-room school, while he and the other men sleep on the mosque's portico.
He has no idea if he'll be allowed to return to the camp that had become his home.
The Rohingya trace their ancestry to what is now Bangladesh, but many have lived in Myanmar for generations. Officially, though, they are dismissed as illegal immigrants. They face widespread discrimination in largely Buddhist Myanmar, and particularly in Rakhine, where many of the Rohingya live.
Tensions remain high in Rakhine nearly a year after sectarian unrest tore through the region and left parts of Sittwe, the state capital, burned to the ground. At least 192 people were killed.
The violence has largely segregated Rakhine state along religious lines, with prominent Buddhists - including monks - urging people not to employ their Muslim onetime neighbours, or to shop in their businesses.
International rights groups and aid agencies urged that the evacuations be stepped up.
The British-based aid agency Oxfam welcomed the government's evacuation efforts, but said "swifter action is needed to ensure people are moved before the storm hits".
"It is essential that humanitarian principles are adhered to in moving all affected populations safely to suitable locations and that no one is left out," the group's director for Myanmar, Jane Lonsdale, said in a statement.
Weather experts have warned that the storm could shift and change in intensity before hitting land.
Myanmar's southern delta was devastated in 2008 by Cyclone Nargis, which swept away entire farming villages and killed more than 130,000 people. Two days before hitting Myanmar, Nargis weakened to a Category 1 cyclone before strengthening to a Category 4 storm.
- AP