Thailand announced a five-day holiday on Tuesday to allow people to escape floods closing in on Bangkok as a major airport was closed when floodwaters covered the tarmac.
The government declared Oct. 27-31 a holiday in Bangkok and 20 provinces affected by the country's worst flooding in 50 years as weekend high tides in the Gulf of Thailand could complicate efforts to divert water from the low-lying capital.
Financial markets will remain open.
As water levels climbed, some of those already evacuated were preparing to be evacuated again, with 4,000 people sheltering at a northern Bangkok airport told they would be moved to the eastern province of Chon Buri.
The floods have killed at least 366 people since mid-July and disrupted the lives of nearly 2.5 million, with more than 113,000 in shelters and 720,000 seeking medical attention.
Authorities are scrambling to pump out water around the east and west of Bangkok but record-high water levels in the Chao Phraya river that winds through the city raise the risk of floods in the commercial heart when the tide rises.
"It's still hard to say whether the water will swell over the Chao Phraya dike but the situation is changing all the time. Things we didn't think would happen have happened," said Seri Supharatid, director of Rangsit University's Center on Climate Change and Disaster.
"In the worst-case scenario, if all the dikes break, all parts of Bangkok would be more or less flooded."
The floods have also forced the closure of seven industrial hubs in Ayutthaya, Nonthaburi and Pathum Thani provinces bordering Bangkok, causing billions of dollars of damage, disrupting supply chains for industry and putting about 650,000 people temporarily out of work.
The cabinet announced a $10.6 billion budget on Tuesday to help rebuild the country, mostly for small- and medium-sized enterprises, small vendors and individuals.
"If they get back to normal quickly, it will help push the economy forward," said Finance Minister Thirachai Phuvanatnaranubala.
Heavy rain late on Tuesday, the first in four days, could complicate an already precarious situation and more showers were forecast for Wednesday.
Don Muang Airport, Bangkok's second biggest, closed late on Tuesday due to concerns that passengers and staff might have problems reaching the terminal. It is expected to reopen on Nov. 1.
Airports of Thailand said the main Suvarnabhumi Airport, was not affected because it was on higher ground. However, Thai Airways International, which operates out of Suvarnabhumi, said it may reduce flights because of staffing concerns.
As water levels rose, there were concerns the Lat Krabang and Bangchan industrial zones in the north and east of Bangkok would be inundated, threatening a total of 344 factories, 49 of which are operated by Japanese firms that include including Honda Motor Co and Isuzu Motors Ltd.
"The situation behind the factory isn't good," Tanapon Karakasikum, an official at an auto components factory at Lat Krabang, told Reuters. "The flood barrier is too low but the operators of the estate are not doing anything."
Residents of the Muang Ake housing estate in northern Bangkok were told to evacuate on Tuesday after a flood protection wall in nearby Pathum Thani province was breached, adding to tension in the capital, where residents have fortified their homes and stockpiled food and water.
The Commerce Ministry said it would relax import tariffs and regulations on food, water and some consumer goods in short supply as a result of hoarding.
Bangkok Gov. Sukhumbhand Paribatra issued a new flood warning late on Monday for Bang Phlad district, west of the Chao Phraya river and closer to Bangkok's commercial heart.
Bang Phlad is home to department stores, universities and hospitals. Siriraj Hospital, where Thailand's revered king has been for more than two years, is nearby.
Government spokeswoman Thitima Chaisang said the holiday had been called due to the high tides and to give residents the option of leaving Bangkok. Sukhumbhand said the holiday would allow authorities to handle the crisis better.
Authorities opened most canal gates in Bangkok late last week, a high-risk operation taking pressure off defensive walls by diverting water around the east and west of the capital into the sea, but raising the chance of inner-city flooding.
Hundreds of people were evacuated over the weekend as water in Lak Si and Don Muang reached levels as high as six feet, spilling out of swollen canals and rivers. Several escaped farm-reared crocodiles have been killed or captured in swamped residential areas of Ayutthaya. Snakes have also been a problem.
At least 227 bank branches have been forced to close by floods, most of them in the provinces north of Bangkok.
If Bangkok floods, authorities will find it hard to cope, said Seri of Rangsit University. "Right now all pumping machines are working on overload. The problem is, once the large mass of run-off water has gone past Bangkok, how are the authorities going to find enough machines to drain the water?"