Residents of one of China's biggest cities are bracing for the arrival of a toxic chemical spill following an industrial accident on its river.
People in the city stocked up on water with the toxic spill en route
Authorities have shut off water to Harbin after confirmation that the accident 10 days ago sent pollution downstream towards the city.
"Benzene levels were 108 times above national safety levels," said China's Environment Protection Administration.
Neighbouring Russia is urgently seeking information from China on the spill.
13 November Explosion at petrochemical plant, Jilin city
21 Nov Water to Harbin city cut off; local government cites mains maintenance
22 Nov State media say water could have been contaminated after the blast
23 Nov Authorities admit very high levels of benzene have been found in the water
It should take two days to pass through Harbin, a city of more than three million people, officials say.
The contamination follows an explosion on 13 November at a chemical plant at Jilin city, about 380km (230 miles) upstream from Harbin, on the Songhua river.
Some schools and businesses have closed and flights out of Harbin are sold out.
"Everyone wants to leave Harbin and it is very difficult to buy tickets," a factory manager told Reuters.
Water was restored to the city briefly on Wednesday to allow people to stock up before the contaminated water reached Harbin.
There have also been reports of frantic well-digging amid fears water from the river could be dangerous for days to come.
More than 16,000 tons of drinking water is being brought into Harbin by road, the Chinese state news agency Xinhua said - though this is less than Harbin's residents normally use in a day.
Benzene is a highly poisonous toxin that is also carcinogenic.
Fifteen hospitals have been placed on stand-by to cope with possible poisoning victims.
Russia's environmental protection agency said it was worried the pollution could affect drinking water supplies in its Khabarovsk region, which the Songhua enters downstream from Harbin.
BBC Beijing correspondent Louisa Lim says residents of Harbin distrust government statements, having originally been told the stoppage was for routine maintenance.
The initial announcement of water stoppages led to panic buying of water and food, exhausting supermarket supplies and sending prices soaring.
"The city was full of ridiculously large queues. People were buying water in massive quantities," English teacher Craig Hutchinson told the BBC News website.
Other residents told the BBC they felt more inconvenienced than worried.
Colourless, highly flammable liquid distilled from petroleum
Used as a cleaning agent, solvent, in dyes and paints
Lethal to humans exposed to it in high levels
Chronic exposure leads to progressive degeneration of bone marrow and leukaemia
"I can say that we feel safe and fine. Even though people... may not be able to shower, at least they can drink and cook with good [bottled] water," hostel manager Yang Yan said.
Environmental officials in Russia said they were also monitoring the Amur river, which is fed by the Songhua and is the main water source for the city of Khabarovsk.
Harbin is in China's north-east Heilongjiang province, and is one of the country's coldest cities, with overnight temperatures this week falling to -12C.
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