(CNN)An explosion has caused a fire at a Russian biological research facility that's one of only two centers in the world known for housing samples of the smallpox virus.
The blast occurred Monday during repair work of a sanitary inspection room at the Russian State Centre for Research on Virology and Biotechnology, known as Vector, near the Russian city of Novosibirsk in Siberia, the center said in a statement.
One worker was injured in the incident and is being treated in intensive care for burns, Russia's TASS news agency reported.
In its statement, Vector said that no biohazard material was being stored in the room where the explosion took place. The city's mayor also insisted that the incident does not pose any biological or any other threat to the local population, according to TASS.
The fire broke out when a gas cylinder exploded on the fifth floor of the six-story laboratory building in the city of Koltsovo. The blast caused windows to smash but there was no structural damage to the building, TASS reported.