Bangkok, Thailand (CNN) -- Bangkok faces the highest flood levels yet and is preparing for the worst, the governor of the Thai capital told CNN. Residents are urged to flee the rising floodwaters, which have already forced the closure of Bangkok's Don Muang airport and the evacuation of flood victims who have taken refuge there. Thailand's government has declared a five-day public holiday in flood-affected provinces to try to encourage people to seek safety elsewhere before high tides expected this weekend. But Bangkok Gov. Sukhumbhand Paripatra told CNN the authorities could not evacuate a whole city and it was difficult to persuade the Thai people to leave their homes, despite the risk.
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NEW: Bangkok's governor warns of the highest water levels in next few days
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Evacuations include 600 inmates at a prison, some animals from a zoo
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PM warns capital could be submerged by as much as 1.5 meters (4.9 feet)
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Authorities: Floods have killed 373 people and affected more than 9.5 million
The Airports of Thailand declared @placeholder airport, which primarily services domestic flights, closed Tuesday night, after floodwaters flowed onto runways and affected the lighting.