About 90 firefighters tried to extinguish the fire, which has engulfed about 20 hectares, the civil protection agency in Kiev said on Saturday.

Two fire-fighting planes and a helicopter were also deployed.

Radioactive radiation still present from the 1986 nuclear accident made fighting the fire more difficult, the agency said, adding that there was no danger to the population.

Fires occur repeatedly in the forests in the exclusion zone.

After the explosion at the Soviet nuclear power plant of Chernobyl in 1986, radioactively contaminated areas around the ruins were closed off and tens of thousands of people forcibly relocated.

Australian Associated Press