Hundreds of Buddhist monks have fled two major towns in eastern Myanmar, witnesses said on Sunday, among thousands of people recently displaced by fighting between the military and rebel groups opposed to last year's coup.

A military power-grab in Myanmar 11 months ago expelled civilian leader Aung San Suu Kyi's government and sparked mass protests and a subsequent crackdown that has killed more than 1,400 people.

Loikaw town in eastern Myanmar's Kayah state saw intense fighting last week that the United Nations estimates has forced almost 90,000 people to flee. Local NGOs have placed that figure far higher at 170,000.

"More than half the population of Loikaw township has been internally displaced," the UN said.

A Buddhist monk told AFP around 30 monasteries had been abandoned -- an unusual sight in a nation where holy men are revered and temples are considered safe havens.

"It was impossible for us to stay there," the monk said, requesting anonymity for his safety.

"It was hard to make the decision to leave, but we had to do it."

The monk, among roughly 5,000 people who have fled Loikaw to eastern Shan state, said 12 monasteries in nearby Demoso town had also been emptied.

A community leader in Taunggyi in Shan state said last week he had seen a group of at least 30 monks arrive in the township seeking refuge.

A Christian priest told AFP about 15 priests also fled Loikaw last week.

Rebel fighters have taken over churches and homes in the town and also attacked a prison, said a policeman who asked for anonymity.

"The town is deserted like a cemetery. The situation in town is very bad," he said.