Wildfires in Russia have grown to catastrophic proportions, forcing evacuation at the country's main nuclear facility, causing a steep rise in the death rate, and wiping out whole villages.

The Russian nuclear agency Rosatom said it had removed all radioactive and explosive materials from the Federal Nuclear Centre near the town of Sarov in central Russia, the birthplace of Soviet nuclear weapons.

The Emergency Situations Ministry said 1,500 fire fighters were battling forest fires around the centre.

The Defence Ministry meanwhile had to remove artillery and missiles from a munitions depot about 70 km southwest of Moscow.

Earlier wildfires razed to the ground a major naval base in the Moscow region, prompting President Dmitry Medvedev to dismiss several senior military officials.

Heavy smog from burning forests, the worst ever in Moscow, choked the Russian capital, blanketing the Kremlin towers and forcing residents to wear masks as pollution rose five times above maximum admissible levels.

The smoke reached into the stratosphere and caused the delay of 140 flights at Moscow airports on Friday.

Emergency officials said fires had already scorched nearly 7,300 square miles, an area about two times the size of Goa.

At least 52 people have died and almost 500 injured in fires, said the Health Ministry.

As of Friday, 588 fires were blazing in European Russia and 248 fires had appeared over the last 24 hours.

A record heat wave that has gripped Russia for more than two months is also killing people.

Health officials privately admit that the death rate in Moscow has dramatically increased, though no official figures are available yet. Funeral agencies say they have twice as much work as they usually do in summer.

Prime Minister Vladimir Putin on Thursday banned all grain exports from Russia till the end of the year amid fears that the country may face a 30-per cent shortfall in cereal crops this year because of the worst drought in decades. The ban has sent world wheat prices to a two-year high as Russia is the world's third-biggest grower and a major exporter of wheat.

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