This is the terrifying moment a temple ceiling collapsed onto Buddhist monks while they were praying.

The three men in orange robes were chanting scriptures in front of a shrine where another elderly monk was sitting when pieces of the rafters started to break away in the building in Khon Kaen, northeast Thailand, on Monday evening August 15.

CCTV footage shows how the monks leapt up and fled when the roof came crashing down on them - with huge pieces of rubble bouncing up at their legs.

Miraculously, none of the monks were hurt other than suffering a few minor scratches in the accident, which is believed to have been caused by several days of heavy rain from tropical storm Mulan which weakened the building's roof.

Monk Phra Thamthorn Bunchu Mahawiro said: 'We only finished three prayers when we suddenly heard a loud crack coming from the top.

'The first object that was only a piece of cloth then the whole thing came crashing down. There was so much dust. We will hire somebody to repair the whole thing.'

'We are lucky none of us was hurt. We only had a few scratches on our legs and feet.'

Several villagers visited the temple to help sweep up the broken pieces. They said the debris filled more than 50 fertiliser sacks and weighed about one tonne.

The collapse is the aftermath of continuous heavy rain crashing down on the temple during Tropical Storm Mulan, which moved up from China last week.

Village council chief Noppakao Pimmahanan said: 'The structure collapsed as it is more than 20 years old. Many birds came and made their nest on the ceiling and also it had been raining a lot recently, which caused it to become weaker.

'I will consult with the villagers on how we will contribute to helping repair the temple. Others who wish to help are also welcome to make donations.'

The torrential weather - which battered China before being downgraded to a tropical depression over Vietnam - caused severe flooding across six Thai provinces.

Department of Disaster Prevention and Mitigation officials said the tropical depression, augmented by a monsoon lying across Myanmar, northern Thailand and northern Laos, caused strong downpours from August 11 to 14.

Thousands of homes across the region were submerged as rescue teams battled to evacuate residents to higher ground, or strengthen flood defences with sandbags. Relief teams were also delivering food and fresh water to residents stranded by the water.

Sandbags were also being used to block the water from spilling into homes and shops while pumps had been brought ini to try and shift the water.

The country's Meteorological Department said Mulan had weakened to a low-pressure cell as it entered Yunnan province in China but the storm has caused widespread heavy rainfall in some of Thailand's northern and northeastern provinces.