Forest fires have swept about 300 hectares of land in the Moscow area, shrouding Russia's capital in thick smog and the strong smell of burning wood. Residents are being advised to stay indoors.
Muscovites, already weary from a record month-long heatwave, awoke to a heavy, gray smog, accompanied by the choking smell of burning wood.
The situation first appeared early this week, but has worsened since then.
Emergency ministry officials in Moscow say 119 forest fires burning in the woodlands in and around the city are to blame. The situation is made worse by burning peat bogs, which smolder underground. Hundreds of firefighters were called to battle the blazes.
The general director of Russia's Meterological Bureau, Alexei Lyakhov, said the immediate weather outlook is not favorable.
Mr. Lyakhov said the situation will get worse, with visibility expected to decrease.
He said Russian meteorologists registered visibility at less than one kilometer.
Mr. Lyakhov said the smoke and smog will linger in Moscow for a few more days. But by Saturday, he predicts there could be a break with the forecast calling for short rains.
In the meantime, Moscow public health officials are warning residents to stay inside and refrain from physical activity. With toxic carbon monoxide levels reported at 20 percent higher than normal, patients with heart and respiratory disease are especially at risk.
Meterologists say it has been at least 30 years since Moscow experienced similar weather.