Ukraine’s state-run energy operator warned Saturday that “there are risks of hydrogen leakage and sputtering of radioactive substances” from the country’s Zaporizhzhia nuclear power plant as shelling in the Russian-occupied area continues, despite international pleas for a ceasefire.

“As a result of periodic shelling, the infrastructure of the station has been damaged,” Energoatom said in a statement, cautioning that “the fire hazard is high” and that the plant “operates with the risk of violating radiation and fire safety standards.”