Death toll rises to 48 as Moscow blanketed by wildfires smog

Passengers on Moscow's subway said a haze was hovering above platforms, stinging the eyes and throat, as City Hall warned of health risks from the smoke carrying harmful gases including carbon monoxide.

Firefighters have extinguished 293 fires, but more than 500 continue to rage over large swathes of countryside, the Emergencies Ministry said in a statement.

Russia is suffering its worst heatwave on record, helping to ignite forest and bog fires across stretches of central and western regions. Dry winds have sent clouds of smog from peat bog fires over Moscow, but yesterday's was the thickest yet, with the haze obscuring the capital's landmarks.

Tens of thousands of troops and volunteers are helping 10,000 firefighters battle blazes in more than a dozen western provinces, seven of which are under a state of emergency.

Moscow weather officials released a statement cautioning the city's 10 million residents to guard themselves against the smoke, saying pollution indicators had reached a "critical barrier" and "even healthy people must take preventative measures".

Emergencies Minister Sergei Shoigu said some wildfires are out of control, contradicting days of reassurances from other officials that the situation was under control.

President Dmitry Medvedev was due to hold a security council meeting to discuss protecting strategic defence facilities, a day after officials confirmed the fires had engulfed a military base near Moscow.