Ukraine’s energy minister said on Friday the situation at the Russian-held Zaporizhzhia nuclear power station was deteriorating because of the psychological state of its Ukrainian staff and the condition of the equipment.

The Ukrainian staff have remained at the plant in southeastern Ukraine since Russian forces captured it last March, soon after Moscow’s invasion. The nuclear plant, Europe’s largest, has repeatedly come under fire, raising fears of a nuclear disaster. Each side blames the other for the shelling.

“The situation is indeed deteriorating. It is getting worse not only because of the mental state of the remaining Ukrainian specialists but also due to the condition of the equipment,” energy minister German Galushchenko told Ukrainian television. The International Atomic Energy Agency, the UN nuclear watchdog, is trying to set up a safe zone around the facility.

The IAEA says it has a permanent presence of up to four experts at Zaporizhzhia but IAEA director general Rafael Grossi has said he is worried the world is becoming complacent about the dangers. Ukraine’s nuclear energy company, Energoatom, has said that Russian forces have continued to build military fortifications around the nuclear power units.