By Alexei Anishchuk
Moscow - Strong winds cleared the toxic smoke from raging wildfires that has choked Moscow for three weeks on Wednesday, but weather forecasters warned that polluting clouds could return in 24 hours.
The smoke in Moscow - which sent pollution levels to the highest levels in decades - almost doubled mortality rates in the capital and disrupted flights, consumer activity and even trading in Russian stocks and bonds.
Muscovites were greeted with a glimpse of clear skies on Wednesday after a thunderstorm accompanied by strong winds in the early hours dispersed the smoke.
The Emergencies Ministry said the area of burning forests in Russia was almost halved in the past 24 hours to 927 square km from 1 740 square km, and that nearly 166 000 people were fighting more than 600 fires.
"The forest fires have not ceased," Roman Vilfand, the director of the state weather forecasting centre, was quoted as saying by Interfax news agency.
"As soon as there is windless weather again, the smoke will return," he said. "It has got easier in Moscow but not where the fires are burning."
Pollution levels in Moscow on Wednesday were at safe levels, but the state weather forecaster said in a statement that the smoke could return by Thursday, depending on the weather.
Kremlin leaders are grappling with Russia's most deadly wildfires since 1972 and a drought that has destroyed crops after what weather monitoring officials say was the country's hottest summer in a millennium.
Some young Russians rejoiced in the rains in the early hours, dancing in the downpour and cheering as thunder and lightning replaced the grey smoke.
The worst heatwave on record could knock 1 percentage point off gross domestic product, according to estimates, weakening a recovery from a 2009 slump due to the global financial crisis.
Prime Minister Vladimir Putin, who has sought to burnish his action-man image and minimise political fallout from wildfires and drought, flew in a firefighting plane that dropped water on a blaze southeast of Moscow. - Reuters