Nearly 400 people have died in Cambodia and Thailand as a result of what officials in the Southeast Asian region are describing as the worst monsoon flooding in decades.
By Wednesday, after several weeks of heavy rain, at least 224 people had been confirmed killed in Thailand and another 167 were found dead in Cambodia.
Keo Vy, spokesman for Cambodia's National Committee for Disaster Management, said that this year's flooding had already exceeded the human and economic toll exacted by the flood season in 2000, which was considered severe.
In a statement to the Xinhua news agency, Vy said the flooding that began in August had now affected the lives of more than 200,000 families in the nation of 14 million.
He said that the flooding of the Mekong River, the region's vital waterway, has inundated an estimated 291,000 hectares of rice paddy, 200km of national roads and up to another 2,019km of gravel roads throughout Cambodia.
In neighbouring Thailand, two months of flooding have inundated 58 of 77 provinces - with 25 still severely affected - and damaged the homes or livelihoods of millions of people, according to the government.
"It's the worst flooding yet in terms of the amount of water and people affected," said an official at Thailand's disaster prevention and mitigation department who asked not to be named.
Since monsoon rains first led to flooding in July, 2.4 million Thais have been affected and nearly 10 per cent of the nation's 22 million acres of rice fields have also been damaged.
Authorities on Wednesday were battling to stop the floods reaching the centre of low-lying Bangkok, as forecasters warned of more wild weather to come.
In the old capital of Ayutthaya, 100km north of Bangkok, several 400-year-old Buddhist temples are at risk of being submerged.
The estimated cost of any damage that may come to the World Heritage Site surrounding the famous Wat Chaiwatthanaram and other temples is $3.2m.
The northern Thai city of Chiang Mai, another popular tourist destination, has also been badly hit.
"The current flood situation is the worst that I have ever seen and it will last until the first week of November," said flood expert Royal Chitradon, director of Thai Integrated Water Resource Management.
"There is a problem of prolonged flooding in central provinces because roads and cities have blocked natural waterways."
Royal said several reservoirs were already full and the western and eastern outskirts of Bangkok were at risk of flooding because of another approaching tropical storm.
Last week, the government announced the deployment of about 10,000 soldiers, backed by 500 military vehicles and more than 100 boats, to help victims. Army bases will also take in evacuees, the military said on Tuesday.