Approaching from the Bay of Bengal, Sitrang is expected to hit the southern coast near the Khepupara area of the Barishal-Chittaging early tomorrow, with winds gusting up to 88kph, the weather office said.

It forecast a storm surge of up to three metres that could swamp mud dwellings along the coast, uproot communication towers and inundate roads.

All the people from the dangerous areas along the coastal belt were being evacuated to safer places, said Enamur Rahman, the junior minister for disaster management.

More than 7,000 cyclone shelters were set up to accommodate three million people, he said.

Aid workers have stockpiled emergency items such as food, tarpaulins and water purification tablets in refugee camps housing more than a million Rohingya in flimsy shelters in Cox’s Bazar.

Officials also advised nearly 33,000 Rohingya refugees, moved from camps to flood-prone island in the Bay of Bengal, to stay indoors.

Authorities in India’s West Bengal were also preparing to face the cyclone. A heavy rainfall alert has been issued coastal areas of West Bengal.

Sanjeev Bandopadhyay, deputy director of the India Meteorological Department, said the cyclone had intensified as it moved over the the Bay of Bengal. It was likely to skirt past West Bengal’s Sunderbans region but several areas would receive heavy rainfalls.

Disaster relief teams were stationed in the coastal towns and tourist attractions such as Digha, Bakkhali and Sagar Island.

Bandopadhyay said water in all the rivers in the Sunderbans delta were rising and may reach up to 10 to 15m during Sitrang’s landfall.

The two neighbouring countries have experienced increasing extreme weather in recent years which has caused large-scale damage. Environmentalists warn that climate change could lead to more disasters, especially in densely populated Bangladesh.