A virus frozen in Siberia for around 30,000 years has been brought back to life after being uncovered by scientists.
The discovery of the virus, named Pithovirus sibericum, under 30m (100ft) of frost has prompted fears that other hidden strains such as smallpox could be exposed by the effects of global warming.
France's National Centre for Scientific Research, which was responsible for the finding in the Chukotka autonomous region, said in a release on its website that the findings "have important implications in terms of public health risks".
"The re-emergence of viruses considered to be eradicated, such as smallpox, whose replication process is similar to Pithovirus, is no longer the domain of science fiction," the organisation said. "The probability of this type of scenario needs to be estimated realistically."
A total of 32 people have died after plane crashed in Siberia shortly after taking off, the news agency AP reports. Eleven survivors remain in a serious condition.
The ATR-72, a French-Italian-made twin-engine turboprop, operated by UTair was flying from Tyumen to Surgut with 43 people on board.
The cause of the crash is not yet clear. UTair published a list of the passengers and crew, with none of them appearing to be from outside Russia.The emergency situations ministry said 12 survivors were flown to a hospital by helicopter, but one of them died there.
At least 29 people have been were killed and 14 were rescued alive from a plane crash in Siberia, Russia's state-run Itar-Tass news agency have said, citing a regional Emergency Situations Ministry official.
The mid-range plane belonging to Russian airline UTair crashed after taking off from Tyumen on a flight to Surgut, an oil town further north in Siberia.