The U.N. nuclear watchdog is due to issue a report on the Zaporizhzhia nuclear power station in Ukraine on Tuesday, a day after shelling cut its electricity supplies for the second time in two weeks and raised fears of catastrophe.

Ukraine and Russia have accused each other of risking nuclear disaster by shelling near Europe's largest nuclear plant, which officials said disrupted power lines on Monday and took the sole remaining reactor offline.

The incident came as Ukrainian forces pressed their counterattacks in the south and east, raising the national flag over a town in Kherson province, a southern region occupied by Russia since the war's early days.