A highly infectious form of bird flu which appears to be moving westwards across Russia towards Europe is being tracked by teams of scientists in Germany and the Netherlands.
The Russian epidemic was first detected in Siberia in July but has steadily spread due to contact between migrating birds and farmed poultry.
Two types of wild duck are being blamed by Russian experts, who say the birds brought the disease from Asia, where it has mutated to affect humans, killing at least 60 people.
In Russia 13,000 birds have died of the disease and 113,000 have been preventively culled. Thirty-six Russian settlements have confirmed cases of the disease, but no cases of human infection have been reported.
Several regions have brought forward the start of the hunting season hoping that possibly infected wild birds will be shot out of the air. Quarantines have been imposed in many regions and the import of Russian poultry into the European Union has been banned.
Scientists in Europe are looking on nervously as the disease appears to have reached the Ural Mountains, the natural dividing point between European and Asian Russia, some 750 miles east of Moscow.
However there were signs yesterday that the disease was not spreading as fast as was feared. Several suspected outbreaks were claimed not to be bird flu after all. Instead, it was claimed, the birds had been poisoned by the wrong kind of feed or had been killed by worms.Reuse content