Russian officials say forest fires are spreading in remote areas of Siberia and the Far East that firefighters cannot reach.

This handout picture taken on July 30, 2019 from onboard a Be-200 firefighting aircraft and provided by the press-service of Russia's Krasnoyarsk Krai's forestry ministry shows a forest fire in the Boguchansky district. (Photo: VCG)

Avialesookhrana, Russia's aerial forest protection service, said Thursday more than 30,000 square kilometers (11,850 square miles) are on fire, with the vast majority in areas that are hard to reach and where potential damage is likely to be less than the cost of fighting them.

Although the fires have not hit populated areas, heavy smoke from them is affecting about 800 communities, officials said, including the large cities of Novosibirsk, Krasnoyarsk and Chita.

Meteorologists say rain is expected in some of the burning areas, but not enough to put out the fires, state news agency Tass reported.