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Recent wildfires in Russia have killed at least 50 people. Firefighters are now focusing on keeping the blazes away from a top-secret nuclear research facility in the city of Sarov.
Officials say the closest blaze was still several miles from the Russian Federal Nuclear Research Centre.
As a precaution, all hazardous materials have been evacuated. Firefighters are using heavy machinery to make fire-breaks in the surrounding forest near the site to prevent the blaze from spreading to the building.
Almost 600 separate fires are still raging, mostly in western Russia.