Residents of one of China's biggest and coldest cities, where water has been shut off for fear of chemical contamination, are jamming the airport and railway stations to get out.
Taps were turned off in Harbin, capital of northeastern Heilongjiang province and famous for its January snow and ice show, at midnight on Tuesday after there had already been panic buying of bottled water and food.
"Everyone wants to leave Harbin and it is very difficult to buy tickets, just like during the Lunar New Year," a factory manager told Reuters.
"All containers are being used to store water, including the bathtub. It will be okay for four days, but not longer than that."
The water supply was shut down after a blast at a chemical plant on November 13 in neighbouring Jilin province only a few hundred metres (yards) from the Songhua River, which supplies water to Harbin, a metropolitan area of nine million people. Five people were killed.
The Beijing Timesnewspaper said the pollutants in the partly frozen river included benzene, an industrial solvent and component of petrol, and that they had reached the city.
"Pollution is definite," said a regional water official, who declined to give his name. "It has entered the Songhua River and has affected the banks and lower reaches."
But state television said no pollutants had reached Harbin by 11 a.m.
Fifteen hospitals are on standby to take in contamination victims, Xinhuanews agency said.
A government notice saying supplies would resume in four days have been removed, raising doubts about how long the crisis would last.