The United Nations' nuclear watchdog said on Sunday that a fire near the Russian-controlled Zaporizhzhia Nuclear Power Plant had "no impact" on the facility's safety.

"No impact has been reported for nuclear safety," the International Atomic Energy Agency said in a statement. Both Kyiv and Moscow said there had been no rise in radiation levels.

In a later statement, the IAEA said it had requested that its team get "immediate access to the cooling tower to assess the damage".

Russia and Ukraine blamed each other for the blaze at the cooling tower outside the plant's perimeter, and the IAEA chief said the conflict between the two sides continues to imperil the Zaporizhzhia facility, which is one of the 10 biggest nuclear plants in the world.

"These reckless attacks endanger nuclear safety at the plant and increase the risk of a nuclear accident. They must stop now," IAEA Director-General Rafael Mariano Grossi said in a statement, without attributing blame for the attack.

The Russian operator of the plant said Ukraine had caused the fire with a military strike but that the reactors were in cold shutdown.

Yevgeniy Balitsky, head of the plant, said the fire occurred "as a result of shelling of the city of Enerhodar by the Ukrainian Armed Forces".

Vladimir Rogov, a member of the Zaporizhzhia administration, said in a Telegram post on Monday the blaze has been "completely extinguished".

Russian nuclear corporation Rosatom said in a statement on Monday that the Ukrainian army's attack on the plant can be characterized as an act of nuclear terrorism.

Russian Foreign Ministry spokeswoman Maria Zakharova accused Ukraine of "nuclear terror" following the attack and urged the IAEA to respond.

Meanwhile, Ukrainian President Volodymyr Zelensky accused Russia of starting the fire.

He posted a video on Telegram on Sunday showing a large plume of smoke coming out of one of the towers on the plant's territory, saying radiation indicators were normal but blamed Russia for using the nuclear plant "to blackmail Ukraine, and all of Europe and the world".

'Dislodging' enemy

On Monday, Russian President Vladimir Putin ordered his army to "dislodge" Ukrainian troops.

"One of the obvious goals of the enemy is to sow discord, strife, intimidate people, destroy the unity and cohesion of Russian society," Putin told a televised meeting with government officials.

Ukrainian forces rammed through the Russian border a week ago and swept across some western parts of Russia's Kursk region. Governor Alexei Smirnov said on Monday the civilian toll has risen to 12 dead and 121 injured.

In the neighboring Belgorod region to the south, Governor Vyacheslav Gladkov said evacuations had begun from the Krasnaya Yaruga district because of "enemy activity on the border".

Responding to a question on Ukrainian troops crossing into Russian territory, China's Foreign Ministry said it has noted the development.

"China's position on the Ukraine issue is consistent and clear," a ministry spokesperson said on Monday. "The Chinese side calls on all parties to observe the three principles for de-escalating the situation, namely no expansion of the battlefield, no escalation of fighting and no fueling the flame by any party."

China will continue to maintain communication with the international community to play a constructive role for the political settlement of the crisis, the spokesperson said.

Agencies contributed to this story.