At least three people were killed, 13 injured and more than 1,000 buildings were damaged when Cyclone Mocha pummeled western Myanmar, state-run media said on Monday.

But refugee camps in southeast Bangladesh for Rohingya Muslims from Myanmar escaped the worst of the storm, although many bamboo huts were damaged, residents of the region said.

It was Myanmar's strife-torn Rakhine State that bore the brunt of the storm, which unleashed winds of up to 210 kph (130 mph) that ripped roofs off homes and brought a storm surge that inundated the provincial capital of Sittwe on Sunday.

More than 850 houses, 64 schools, 14 health facilities and seven communication towers in Myanmar were destroyed or damaged by the storm, one of the most powerful to hit the country in years, military-owned Myawaddy TV news channel said.

A junta spokesperson did not immediately answer a telephone call from Reuters seeking comment.

A spokesman for the Arakan Army militia force in Rakhine State said it was using its communication equipment to gather information on the impact of the storm because civilian networks had been severely disrupted.

The U.N. humanitarian office (OCHA) said about 6 million people in the region were already in need of humanitarian assistance before the storm, among them 1.2 million people internally displaced by ethnic strife.

OCHA officials were assessing damage to camps for displaced people, which are near the coast and mostly made of bamboo, and evacuation centres, a spokesperson said.

In 2008, Cyclone Nargis swept across parts of southern Myanmar killing nearly 140,000 people.

Before Cyclone Mocha made landfall on Sunday afternoon about 400,000 people were evacuated in Myanmar and Bangladesh, as authorities and aid agencies scrambled to avoid heavy casualties.

The majority of buildings in Sittwe were damaged, including the main hospital that lost parts of its roof, a resident said by telephone.

In neighbouring Chin State, which has seen heavy fighting between the junta forces and pro-democracy insurgents, activists were having difficulty in trying to access the impact of the storm in areas under a junta communications blackout.