STORY: :: Volodymyr Zelenskiy via Telegram

This video of smoke spewing from a nuclear cooling tower is what Ukraine's leader Volodymyr Zelenskiy claims shows a fire at the Zaporizhzhia nuclear power plant.

:: Russian National Guard Press Service

He claimed Sunday without evidence it had been set by Russian forces which now occupy the plant, seen here in Russian national guard handout video.

Both sides are accusing the other of setting a fire on the grounds of the plant, Europe's largest nuclear facility

Russian state news agency RIA said that a drone attack started the fire, also without providing evidence.

However, both sides also say there's no sign of elevated radiation.

The fire comes less than a week after Ukraine's forces launched their largest incursion into Russian territory since the war in Ukraine began in 2022.

The six reactors at the plant are close to the front line of the war in Ukraine.

They are not in operation, but the plant relies on external power to keep its nuclear material cool and avoid catastrophe.

The UN's nuclear watchdog, the IAEA, which has a presence at the facility confirmed its experts had seen strong, dark smoke coming from the plant's northern area.

:: File

IAEA chief Rafael Grossi says its agency has requested quote 'immediate access' to the cooling tower to assess the damage.

There was no immediate response to his statement from Moscow or Kyiv.