A toxic spill from a Chinese factory is now threatening the Russian city of Khabarovsk, where 580,000 people now face pollution and the possibility that their heating may have to be switched off despite sub-zero temperatures.

A toxic slick from a Chinese plant explosion has picked up speed toward Russia and is due to cross the border in about three days, Alexander Gavrilov, the head of the Russian Far East Meteorological Service, said today.