A huge blaze that tore through forests around Chernobyl has been put out, Ukrainian officials say.

Photo: Volodymyr Shuvayev / AFP

The officials said hundreds of emergency workers had used planes and helicopters to douse the flames.

Environmental activists had warned on Monday that the fire, near the site of the world's worst nuclear disaster in 1986, posed a radiation risk.

Chernobyl tour operator Yaroslav Yemelianenko, writing on Facebook, had described the situation as critical, saying the fire had reached the abandoned city of Pripyat, 2km from where "the most highly active radiation waste of the whole Chernobyl zone is located".

But Ukrainian authorities said on Tuesday that though they had registered short-term spikes in Caesium-137 particles in the Kiev area to the south of the plant, radiation levels remained within normal limits overall and did not require additional protection measures.

"There is no open fire," the Interior Ministry said in a statement. It added that there was "a slight smouldering of the forest floor" however.

Photo: Volodymyr Shuvayev / AFP

President Volodymyr Zelenskiy has promised transparency on the issue and will meet the head of the emergency services later on Tuesday.

"Society must know the truth and be safe," he said in a statement late on Monday.

The fire, one of several which followed unusually dry weather, began on 3 April in the western part of the exclusion zone and spread to nearby forests.

Police say they have identified a 27-year-old local resident who they accuse of deliberately starting the blaze.

It remains unclear if the person, who has reportedly confessed to starting a number of fires "for fun", is partly or fully responsible.

-Reuters