Radiation from fires that have torn through forests around Ukraine's defunct Chernobyl (Chornobyl) nuclear power plant poses "no risk to human health," the U.N. atomic agency said on Friday, based on data provided by Ukraine.

The main fire among several blazes was extinguished last week but advanced far into the 30 km exclusion zone around the plant, the site of the world's worst nuclear accident in 1986. Smaller fires are still burning in the exclusion zone, its administration said on Friday evening, Reuters said.

Read alsoNASA says it sees fires near Chornobyl break out again (Satellite image)

Видео дня

Footage from the site has shown plumes of smoke billowing from the charred landscape, and environmental activists have said the burning of contaminated trees and other vegetation could disperse radioactive particles, posing a health risk.

"The recent fires in the Exclusion Zone near the Chernobyl Nuclear Power Plant in Ukraine have not led to any hazardous increase of radioactive particles in the air," the Vienna-based International Atomic Energy Agency (IAEA) said in a statement.

The Vienna-based IAEA, which acts as the U.N. nuclear watchdog but also aims to encourage the peaceful use of nuclear energy, said it was basing its assessment on data provided by Ukraine.

Read also"No threat to Chornobyl facilities": PM reports on wildfire response progress in northern Ukraine

The IAEA said it found "the increase in levels of radiation measured in the country was very small and posed no risk to human health."

There had been "some minor increases in radiation," the IAEA said, adding the State Nuclear Regulatory Inspectorate of Ukraine had found "the concentration of radioactive materials in the air remained below Ukraine's radiation safety norms."