Authorities in the Thai capital Bangkok are urging residents of two outlying districts inundated with flood waters to evacuate their homes and take refuge in nearby shelters.

Bangkok Governor Sukhumbhand Paribatra issued the warning late Wednesday for residents in the Don Muang and Bang Phalad districts, both of which are nearly completely submerged. The airport in Don Muang, the second largest in Bangkok, has been shut down.

Meanwhile, scores of residents are using a government-imposed five-day holiday to escape flood waters that are expected to swamp the city later this week. Thousands of people are packed into bus terminals and Bangkok's main international airport, while highways leading out of the city are choked with thousands of cars carrying panicked residents.

The Chao Praya River is on the verge of breaching its banks due to high sea tides, with Prime Minister Yingluck Shinawatra saying the floodwaters could be as deep as 1.5 meters by the end of the week.

Unusually heavy monsoon rain has caused flooding since mid-July that has killed at least 373 people across Thailand.