A toxic river spill from a chemical explosion in China has reached Russian waters, Moscow has said.
The leak is due to reach Khabarovsk in four to five days
Russian Emergencies Minister Sergei Shoigu said checks carried out in the Amur river so far showed toxicity levels to be normal.
He said arrangements were in place to purify water, and new wells had been drilled to ensure safe supplies.
The 100-tonne spill is expected to reach the main city in the area, Khabarovsk, in four to five days.
"The water polluted with benzene today reached the Russian border and has flowed into the Amur River," Mr Shoigu said.
Chinese media reported that the spill had significantly diluted in the Songhua River before entering the Amur.
About 50 tonnes of chemicals have been flown in to treat the benzene in the water upstream of Khabarovsk, which has 600,000 inhabitants.
But Mr Shoigu said the city's central water system would be switched off only in "extreme circumstances".
The first population centre inside Russia to be affected by the contamination was expected to be Nizhne-Leninskoye.
The leak has been flowing down the Songhua River in China following the blast at a petrochemical plant on 13 November in the city of Jilin.
The spill affected the city of Harbin's 3.8m population, who endured five days with no running water.
Beijing has apologised to Russia for the pollution entering its rivers.