The Ukrainian leader warned of "dangerous provocations" at Zaporizhzhia, while Moscow countered with similar allegations of Kyiv planning an attack on the plant.
The UN's International Atomic Energy Agency (IAEA) said on Wednesday its experts saw no indications of mines or explosives at the Russian-held Zaporizhzhia nuclear power plant, yet added that they needed more access to be certain.
Experts at the plant "have in recent days and weeks inspected parts of the facility - including some sections of the perimeter of the large cooling pond - and have also conducted regular walkdowns across the site, so far without observing any visible indications of mines or explosives," an IAEA statement said.
The experts requested additional access, the agency said. They are particularly after access to the rooftops of reactor units 3 and 4, as well as parts of the turbine halls and some parts of the cooling system at the plant.
IAEA did not specify why the named locations were particularly important.
"With military tension and activities increasing in the region where this major nuclear power plant is located, our experts must be able to verify the facts on the ground," the agency said. The statement came as both Ukraine and Russia exchanged accusations over planned attacks at the plant.
An explosion rocked a court in the Ukrainian capital on Wednesday, with a man taken to a court hearing dying after attacking guards with explosives.
The explosion occurred in the Shevchenkivskyi court in central Kyiv, the capital's city military administration said.
An Interior Ministry statement citing Ukrainian Interior Minister Ihor Klymenko said the perpetrator locked himself in a toilet then threw explosives at the guards, before trying to exit the court building.
Two officers were injured in the attack, the ministry said, adding that they were not in critical condition. The police was investigating how the perpetrator smuggled the explosives into the court.
No civilian casualties were reported, the ministry said.