Dhaka, 14 May 2023 (dpa/MIA) — Rainbands and wind gusts of the powerful Cyclone Mocha were lashing coastal areas of Myanmar and Bangladesh, causing initial damage to local communities, those tracking the escalating storm said on Sunday.

The Global Disaster Alert and Coordination System (GDACS) put the cyclone on red alert and expects destructive winds of up to 259 kilometres per hour in Myanmar and neighbouring Bangladesh. Mocha had been gaining strength over the Bay of Bengal for days.

"The storm has started since the morning and now it is moving strongly. But it has not yet reached its highest strength," said Kan Aung, a resident of the Myanmar city of Sittwe and member of a local team covering the situation.

Phone lines and internet connections were down in coastal areas, while trees were being uprooted small buildings were damaged in the high winds, the 21-year-old told dpa on Sunday.

Sittwe and large parts of Mynamar's Rakhine State are calculated to be exactly on the cyclone's route. It is around 180 kilometres south-east of the city of Cox's Bazar in Bangladesh.

Around 1 million Rohingya refugees from Myanmar live in Cox's Bazar in makeshift shelters. People were told to stay away from the coast, where violent tidal waves were expected.

About 300,000 people came to cyclone shelters under arrangement by the Bangladeshi government, said Bibhisan Das, an official working with emergency response control room in Cox's Bazar district.

Dhaka's Met Office said the low-laying areas of the coastal districts of Cox’s Bazar and adjoining Chattogram and offshore islands are likely to be inundated by a wind-driven tidal surge of nearly 2.5 meters above normal.

Khameni Sikder, a resident of Saint’s Martin island in the Bay of Bengal, told private broadcaster Channel24 that many trees were uprooted and tin-roofed homes damaged by the gusts.

Bangladeshi meteorologist Azizur Rahman said Mocha's wind speed had decreased to between 160 kilometres and 180 kilometre per hour by Sunday afternoon, from 225 kilometres per hour earlier.

Rahman forecasted that the worst of the storm would largely spare Cox’s Bazar.

Many in the region are afraid that Mocha could wreak similar devastation to Cyclone Nargis 15 years ago. On May 2-3, 2008, the tropical storm in Myanmar's Irrawaddy Delta is estimated to have killed almost 140,000 people.

"Families are scared," Kan Aung from Myanmar. "The storm will probably be as powerful as Nargis - we can only pray."