Smoke from wildfires in the contaminated evacuation zone around the wrecked Chernobyl nuclear power plant has engulfed Kyiv, placing the Ukrainian capital near the top of the global air pollution index.

Authorities said radiation levels in Kyiv have remained normal, but advised residents to stay home and close their windows.

About 1,000 firefighters backed by aircraft have been deployed to battle the forest blazes near the site of the world’s worst nuclear accident, which took place 34 years ago.

Wildfires erupted in the forests around Chernobyl on April 4, accidentally sparked by residents who were burning rubbish. The firefighting teams managed to contain the initial blazes, but new fires erupted on Thursday, sweeping into wider areas thanks to strong winds.

The scene from the roof of the Chernobyl nuclear power plant
The scene from the roof of the Chernobyl nuclear power plant (Ukrainian Police Press Office/AP)

Live air quality data on placed the Ukrainian capital right behind several cities in China in air pollution on Friday.

Authorities in Kyiv said radiation levels in the capital, about 60 miles south of the plant, were within norms. They also insisted the wildfires were posing no threat to radioactive waste dumps and other facilities at Chernobyl, but advised Kyiv residents to drink a lot of water and cover windows with wet fabric if they open them.

The fires are in the 1,000 square mile) Chernobyl Exclusion Zone established after the 1986 disaster at the plant that sent a cloud of radioactive fallout over much of Europe.

The zone is largely unpopulated, although about 200 people have remained despite orders to leave. Fires in the area raise concerns that they could spread radioactive material.