KYIV, Ukraine (AP) — Ukraine's state nuclear energy operator said Friday that Europe's largest nuclear power plant, caught in the Ukraine-Russia war, is operating in emergency mode with elevated risk.

The six-reactor Zaporizhzhia Nuclear Power Plant came under the control of Russian forces early in the war that started in February, but is being operated by Ukrainian staff. The plant and surrounding areas have been repeatedly hit by shelling that Russia and Ukraine blame on each other's forces.

The last power line connecting the plant to the Ukrainian electricity grid was cut on Monday, leaving the plant without an outside source of electricity and receiving power for its own safety systems from the only one of the six reactors that remains operational.

Energoatom, the state nuclear operator, said Friday that repairs to the outside lines are impossible because of the shelling and that operating in the so-called “island” carries "the risk of violating radiation and fire safety standards.”

"Only the withdrawal of the Russians from the plant and the creation of a security zone around it can normalize the situation at the Zaporizhzhia NPP. Only then will the world be able to exhale,” Petro Kotin, the head of Energoatom, said Friday on Ukrainian TV.

Fighting continued Friday in parts of southern and eastern Ukraine and in the north where Ukraine claims to have recently pushed Russian forces out of some areas.

Russian planes bombed the hospital in the town of Velika Pysarivka, on the border with Russia, said Dmytro Zhyvytskyi, governor of the Sumy region. he said the building was destroyed and there were an unknown number of casualties.

Four people were killed in shelling in the Kharkiv region, two of them in Kharkiv city, Ukraine's second-largest, according to regional governor Oleh Syniehubov. Ukraine this week claimed to have regained control of more than 20 settlements in the Kharkiv region, including the small city of Balakliya.

Social media posts showed weeping and smiling Balakliya residents embracing Ukrainian soldiers.

In the Donetsk region in the east — one of two that Russia declared to be sovereign states at the outset of the war — eight people were killed in the city of Bakhmut over the past day and the city is without water and electricity for the fourth straight day, said governor Pavlo Kyrylenko.