Floodwaters in Thailand are creeping closer to the heart of Bangkok, with authorities warning millions to leave their homes in six city districts including areas just north of the city centre.
City officials said on Sunday that residents in the six districts faced "potential dangers to lives and properties" and urged them to move to emergency shelters.
"If anything affects Bangkok it will have an impact on the whole country, so it's very important to take care of Bangkok in order for the country to survive," Sukhumbhand Paribatra, the Bangkok governor, said in a televised address.
"In particular, priority must be assigned to the sick, young and elderly," said the statement, asking the public not to panic.
Hundreds of people were evacuated over the weekend as water in residential areas of the northern Lak Si and Don Muang suburbs reached levels as high as two metres.
Al Jazeera's Wayne Hay, reporting from Bangkok, said that flood water has already inundated the low lying areas of the capital.
"Governor of Bangkok has acknowledged that the flood waters are moving faster than anticipated," he said.
The six Bangkok districts now of pressing concern include Chatujak, home to a giant weekend market popular with tourists, and Don Mueang, where the city's second largest airport is currently doubling up as a flood refuge centre.
Supong Limtanakool, vice president, Bangkok University, told Al Jazeera: "For the past few days the information we have received from flood control authorities have been very very contradictory, resulting in people getting panicked.
"Misinformation is being given there, and there is no direct co-ordination between different government agencies," he said.
Thai government criticised
The Thai government headed by newly elected Yingluck Shinawatra has been criticised for its handling of the situation.
But the Thai prime minister has rejected criticism and said that her administration was not keeping the public fully informed, telling reporters there was "no cover-up but new factors arise every day".
"There are several factors that we can't control. The water is coming in two directions," Yingluck said.
Al Jazeera's Hay said: "The PM has been resisting calls to declare a state of emergency. Instead, she enacted a special disaster law which gives her greater authority."
"And one of her first job was to instruct the army and ministry of defence to protect key areas around Bangkok city in case the floods spread to commercial heart of the city, including Grand Palace and the city's two airports," he said.
Airport officials have said the roads by the terminals were swamped by 70-80 centimetres of water and had become impassable for small vehicles, though the Don Mueang compound itself remained dry for now.
Hundreds of worried residents have parked cars on bridges and elevated roads. Adding to concerns were photographs and televised footage of sizeable crocodiles captured by villagers and authorities in a province north of Bangkok, after a number of the reptiles escaped from flooded farms.
The World Health Organisation has warned that infections, water-borne and communicable diseases, such as diarrhoea, were key concerns for flood victims, who were also warned to be beware of electrocution and snake bites.
Stockpile of medicines
Hospitals in flood-risk zones have been told by the public health ministry to stockpile medicines and other supplies to last as long as three weeks.
The government has said it would discuss measures in a cabinet meeting on Tuesday to help the nation's hundreds of flood-affected factories get back on track, with financial aid and tax incentives among the ideas mooted.
Another major test is expected between October 28 and 30 when seasonal high tides flow up Bangkok's Chao Phraya river, meeting run-off water from the north.
Other parts of the country have been plagued by three months of heavy monsoon rains, which have killed more than 350 people in Thailand and damaged the homes and livelihoods of about nine million people.