"There is no open fire," the emergency services said in a statement, adding that radiation levels are within the norm.

Chernobyl polluted a large swathe of Europe when its fourth reactor exploded in April 1986. People are not allowed to live within 30 kilometres (18 miles) of the power station.

Police have said the fire was sparked on April 4 by a man burning dry grass near the exclusion zone around the ruined reactor. The flames spread quickly, fanned by strong winds.

Kiev has mobilised helicopters and more than 400 firefighters, with planes dropping hundreds of tonnes of water on the fire.

Ukraine President Volodymyr Zelensky said late on Monday he is "closely" following the situation and was "grateful for the courage" of the firefighters.

On Tuesday the president said he will hear a report from the chairman of the emergency service and that "society should know the truth and be safe."

Oleksandr Syrota, head of the Chernobyl information centre, welcomed reports of rain in the exclusion zone as "good news" on Facebook.

The interior ministry's spokesperson said rain "has greatly helped rescuers who have been fighting with fire in the area for over a week".

- 'Unpredictable' -

While forest fires are common in the exclusion zone, Greenpeace Russia said Monday that this is the worst since the 1986 nuclear explosion.

The environmental campaign group said that analysis of satellite images showed the fire at its closest point was just 1.5 kilometres (less than a mile) from the protective dome over the ruined reactor.

Sergiy Zibtsev, head of the Regional Eastern European Fire Monitoring Center, told AFP that the fire is "super-huge" and "unpredictable".

"In the west of the exclusion zone it has already covered 20,000 hectares (50,000 acres) by our calculations."

The Ukrainian emergency service has not provided recent figures on the size of the fire, but said that "there is no threat to the Chernobyl nuclear power plant and the storage facilities".

Government agencies have insisted the fire has not caused a spike in radiation levels.

After the 1986 explosion, the three other reactors at Chernobyl continued to generate electricity until the power station finally closed in 2000. A giant protective dome was put in place over the fourth reactor in 2016.

osh/jbr/wdb

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