Russia once again hit Ukraine with drone strikes early on Friday, causing a major power outage in the industrial city of Kryvyi Rih, which is the birth place of President Volodymyr Zelensky.
Tens of thousands of households and numerous companies in the city in the south-east of the country were cut off due to damage to a plant, according to the Ukrainian energy company Ukrenergo.
The regional governor Serhij Lysak announced that two mining shafts were also affected by the power outage, with 100 workers underground at the time.
Lysak said some of them had already been brought to the surface.
According to the authorities, work was under way to restore power supply.
The massive drone attack mainly affected the southern and central parts of the country, Ukrenerho added.
The Ukrainian air defence reported that a total of 11 of 24 Russian drones had been shot down.
Ukraine has been fighting with Russia for almost two years.