Ukraine's state nuclear power company says a Russian rocket attack has severed the last outside power supply to the Zaporizhzhia plant in the country's south.
Energoatom says the electricity supply was cut before 4 a.m. on Thursday.
The firm says the plant uses reserve generators to supply power needed for the plant's functioning.
But it says it has enough fuel for only 10 days, and that failure to restore power will lead to a serious situation.