Russia and Ukraine traded accusations over a scare at a nuclear power plant on Thursday and were urged not to “roll the dice” by attacking the site.
Ukraine accused Russia of telling a “web of lies” over the incident at Zaporizhzhia last Sunday in which a drone exploded on a reactor dome.
Moscow asked the International Atomic Energy Agency to condemn Kyiv over what it said was an attack by Ukrainian combat drones.
Rafael Grossi, the head of the IAEA, stopped short of blaming either side at an emergency board meeting in Vienna on Thursday.
But he warned military commanders on both sides not to open a “new and gravely dangerous front of the war” with “reckless attacks”.
Reports of a further skirmish on Tuesday were “an ominous indication of an apparent readiness to continue these attacks”, Mr Grossi said.
The drone attacks “fortunately did not compromise nuclear safety in a serious way, but it would be irresponsible for us to assume future attacks will not”, he said.
“Rolling the dice is not the way to do it in nuclear safety.”
Moscow circulated pictures of what it said was a five-pronged attack on the Zaporizhzhia plant, which is occupied by Russian forces.
It said three people were injured when a drone hit the plant's canteen, with others hitting a training centre, a cargo port and a reactor dome and a fifth being shot down.
Russia is “firmly convinced” that the IAEA and its member states should “condemn these terrorist acts” by Ukraine's armed forces, said its delegation in Vienna.
Nataliia Kostenko, the deputy head of Ukraine's mission, said threats to the plant were “a direct consequence” of Russia's invasion.
“Russia's attempt to pin the blame on Ukraine is a desperate effort to hide its guilt,” she said.
“We urge the international community to see through Russia's web of lies. The reality is obvious – Russia deliberately creates nuclear threats at the Ukrainian peaceful nuclear facility, which it continues to occupy.”
Mr Grossi said the attacks were the first observed at the plant since November 2022.
IAEA staff stationed at the site saw damage at one of Zaporizhzhia's six reactor buildings, which are not currently producing power, the agency said.
Remnants of drones were found at three sites, with blood stains discovered next to a damaged military vehicle, but there was no significant damage to the reactor.
In a second incident on Tuesday, the IAEA staff reported hearing bursts of rifle fire followed by a loud explosion.
They were denied access to inspect a training centre, Mr Grossi said, leaving it unclear what had happened.
“I urge you to make this your highest priority and to support me and the IAEA in doing everything in your power to stop this devastating war becoming unconscionably more dangerous,” he told member states.
