VIENNA: The Zaporizhzhia nuclear power plant in Ukraine has been without off-site power for more than a week and is currently relying on emergency diesel generators, the UN's nuclear watchdog said Saturday.

The plant, which needs power to keep its six non-operating reactors cool, has only a ten-day diesel supply on site, the International Atomic Energy Agency said in a statement.

It has not had a delivery to an off-site storage facility in about six months, but the plant had been supplied with diesel Thursday and Friday from another off-site location, the IAEA added.

"The availability of diesel fuel is of paramount importance whenever a nuclear power plant loses off-site power," said IAEA Director General Rafael Grossi.

"The current situation once again shows why reliable external power and secure supply routes are indispensable for nuclear safety and security."

The plant lost its regular power supply "following military activity on the northern side of the Dnipro River", the statement said.

The Vienna-based group said it was trying to negotiate a local ceasefire to allow repairs to electrical lines.

On Friday, the IAEA said there had been three incidents this week involving drones at the Zaporizhzhia plant, injuring two employees, and raising renewed safety concerns.

The plant, in southern Ukraine, was seized by the Russian army in March 2022, just weeks after its full-scale invasion.

Both sides in the conflict regularly accuse the other of attacking the site on the banks of the Dnipro river that marks the frontline in the sector.

IAEA teams have had a permanent presence at the plant since September 2022. Zaporizhzhia's six reactors have been shut down since 2022.