Sweltering temperatures in Russia have reportedly tripled the number of forest fires engulfing the Moscow region over the weekend.
Emergency crews are still battling the flames caused by the worst heatwave and drought since records began 130 years ago.
At least 52 people have died, dozens have been hospitalised and thousands have been left homeless by the inferno.
Large swathes of Russia continue to burn, including areas dangerously close to the Russian Federal Nuclear Centre in Snezhinka.
Russia’s Emergency Minister Sergey Shoygu told firefighters: ‘‘As long as there is a threat to this potentially dangerous site. I am asking you to target all your forces to halt this threat. Actually, I’m not asking, I’m commanding. Only, when this threat is ended can you start to focus on the national parks.’‘
The acrid smoke has delayed dozens of flights at the capital’s busy airports and comes amid growing criticism of the government’s response to the crisis.