The spill was caused by an explosion on 13 November at a Chinese chemical factory. It poured tons of dangerous chemicals into a river which flows into the Amur river on the Russian-Chinese border.
The spill is passing settlements in northeast China and is now expected to drift into the Amur sometime during the next 10 days.
China has apologized to Russia for the spill and said it is willing to help Russia deal with the contamination. The head of Russia's Federal Water Resource agency (Rustem Khatimov) said on 29 November China has promised to compensate Russia for ecological damage, but China has n-t confirmed this.