A devastating wave of wildfires across Russia could ravage millions of acres of forests and cause worse damage than last year's catastrophic forest and peat-bog fires, environmentalists and officials said on Thursday.

"We're burning, burning badly," Greenpeace's forestry expert, Alexey Yaroshenko, said. "This year's situation is already much worse than last year's."

In 2010, an unprecedented heat-wave triggered fires that killed 55 people, destroyed thousands of houses and 2.6 million hectares (6.4 million acres) of forests, an area slightly larger than Oregon.

This year, three firefighters have died, and dozens of wildfires have already engulfed more than 600,000 hectares (1.48 million acres) of forests, nearly three times more territory than this time last year, the emergencies ministry reported.

Greenpeace claimed that the government is silencing information about fires, especially about the renewal of peat-bog fires around Moscow that cloaked the capital with acrid, toxic smoke last year.

"There are dozens of them around Moscow," Greenpeace's Grigory Kuksin told journalists. "It's technically impossible to put out some of them already."

Once ignited, peat-bogs can smolder for months or years, surviving heavy rains and snow. While burning, they emit acrid smoke that can aggravate asthma, bronchitis and heart conditions. Moscow last year was engulfed in a thick blanket of smog that combined with the intense heat doubled the death rate.