Since dawn, Moscow's troops "shelled Energodar with mortars and used automatic weapons and rockets," Mayor Dmytro Orlov said on Telegram, publishing photos of damaged buildings in the Russian-occupied territory with smoke spiralling above them.

"We demand that Russia stops its provocations and gives the IAEA access to this Ukrainian nuclear installation," Orlov said, referring to the UN nuclear watchdog.

A 14-member team from the International Atomic Energy Agency (IAEA) is expected to arrive at the Zaporizhzhia nuclear plant on Thursday.

"My mission is... to prevent a nuclear accident and preserve the largest nuclear power plant in Europe," IAEA director general Rafael Grossi told reporters.

"We are preparing for the real work," he said. "We are going to try to establish a permanent presence for the agency."

Fresh shelling struck Energodar, the city housing the plant, on Wednesday, stoking global concern.

Both sides have repeatedly traded blame over attacks in the area.