The International Atomic Energy Agency says renewed shelling at the Zaporizhzhia nuclear power plant in Ukraine has damaged cables providing electricity to one of its six units.

The plant in southeastern Ukraine temporarily lost external power earlier this month due to heavy shelling.

The plant's power supply had since been restored, and the area was relatively quiet.

But in a statement released on Wednesday, IAEA Director General Rafael Grossi said pre-dawn shelling near the turbine hall of one of the plant's six units damaged cables providing electricity to that unit.

The statement said emergency diesel generators went into operation for about 40 minutes to maintain the unit's cooling function before power was restored. All of the plant's six units are currently in a state of cold shutdown.

Grossi expressed concern, as Wednesday's shelling followed one the previous day on the plant's premises. He reiterated the need to establish a security protection zone around the plant.

Petro Kotin, the president of Ukraine's state nuclear power company Energoatom, told NHK earlier this month that all safety problems would be resolved if Russian forces were to leave the plant.