Russian authorities confirmed Wednesday that wildfires have started in some forests contaminated by the 1986 Chernobyl nuclear disaster, according to media reports.

Fires have engulfed about 3,900 hectares in several southwestern regions hit by the Chernobyl fallout, though most of those blazes have been extinguished, Vasily Tuzov, a deputy head of the federal forest protection service, told The Associated Press.

Emergency Situations Minister Sergei Shoigu last week acknowledged the danger from fires in the contaminated regions. He told the AP on Wednesday, however, that ``the situation here is not as difficult as in the areas around Moscow."

Pollution caused by the fires has forced the evacuation of children and elderly people from Moscow to southern Russia as well as to Ukrainian sea resorts, the RBC news agency reported, citing a high-ranking city official.

Irina Yegorushkina, an Emergency Situations Ministry spokeswoman, said experts from Moscow determined there has been no increase in radiation levels in the Bryansk area, a region on the border of Belarus and Ukraine hit hard by the Chernobyl disaster.

Emergency Situations Ministry official Vladislav Bolov insisted Wednesday that a check of the areas contaminated by Chernobyl this week proved the fires had not spread any radiation, the ITAR-Tass news agency reported.

The Bryansk forest protection service has increased patrols around the Bryansk forests, particularly in the southwest section affected by Chernobyl, agency chief Vladimir Rozinkevich said.

``There is a danger, but we are controlling the situation,'' he said.

Large forested areas in Bryansk were contaminated when the Chernobyl nuclear power plant's Reactor No. 4 exploded during a pre-dawn test on April 26, 1986, spewing radioactive clouds over much of the western Soviet Union and northern Europe.

Radioactive particles settled into the soil and environmentalists have warned that they could be thrown up into the air once again by wildfires and blown into other areas by the wind. They said, however, that doses would likely be small.

Earlier this week, Russia's chief sanitary inspector Gennady Onishchenko denied reports about fires in the "radioactive woods" about 350 km from Moscow.

Onishchenko, who is also head of the consumer protection watchdog Rospotrebnadzor, urged the media not to "spread panic."

Hundreds of wildfires sparked by the hottest summer ever recorded in Russia have engulfed large areas of western Russia.

About 165,000 workers and 39 firefighting aircraft were battling more than 600 blazes nationwide Wednesday over 220,000 acres (more than 90,000 hectares), the Emergency Situations Ministry said.