Moscow flights diverted as smog strikes; WORLDBULLETINS.
Runway visibility was down to as little as 220 yards at times, while in central Moscow it was a few dozen yards.
Airborne pollutants such as carbon monoxide were four times higher than average readings - the worst seen to date in the Russian capital.
Kremlin spires and church domes disappeared into the dirty mist, which was forecast to hang around for days due to the lack of wind.
More than 500 separate blazes were burning nationwide yesterday, mainly across western Russia.
Dozens of forest and peat bog fires around Moscow have ignited.