The Vienna-based International Atomic Energy Agency (IAEA) said Ukrainian authorities have informally informed the IAEA that workers of the now-defunct Chernobyl nuclear power plant were at risk due to continued Russian shelling of checkpoints in Slavutych.

According to the UN watchdog, many employees working at the plant live in the city located outside of the Exclusion Zone that was established around the site after the 1986 nuclear catastrophe.

The IAEA cited Ukraine’s regulatory authority on Thursday as saying that the shelling was endangering “the homes and families of those operational personnel that ensure the nuclear and radiation safety” of the plant, which fell to Russian forces on February 24.

The content rotation ban prevented further rotation of personnel to and from the site.

Although operations stopped at the plant after the disaster, Chernobyl was never completely abandoned and still requires constant management.

IAEA Director General Rafael Mariano Grossi has expressed concern over the development, which comes just a few days after technical staff at Chernobyl were finally able to rotate and go to their homes in Slavutych and rest after working for nearly four weeks without a change of shift.

He said the IAEA would continue to closely monitor the situation.

The Ukrainian regulatior said that out of the country’s 15 reactors at four sites, eight were continuing to operate, including two at the Russia-controlled Zaporizhzhya plant, three at Rivne, one at Khmelnytskyy, and two at South Ukraine.