Russian forces have reportedly handed control of the Chernobyl nuclear power plant back to Ukraine and withdrawn troops after Russian troops entrenched in the area suffered radiation poisoning from kicking up toxic dust.

Russia took control of the defunct plant the day after President Vladimir Putin ordered the invasion of Ukraine on Feb. 24 but allowed Ukrainian personnel to continue running the station, which was the site of a catastrophic nuclear meltdown in 1986 and remains a highly radioactive area today. Although the Chernobyl power plant is no longer operational, its radioactive remnants require constant management.

Managing the toxic environment surrounding Chernobyl apparently became too much for Russia's forces to handle. The International Atomic Energy Agency (IAEA) said on Thursday that Ukraine had informed the agency that Russian forces had formally “transferred control of the [plant] to Ukrainian personnel and moved two convoys of troops to Belarus.”

The exodus of Russian military will provide some relief to the workers running the site. Staff at Chernobyl normally rotate shifts regularly, but after the Russian occupation, the team working in the so-called dead zone was unable to rotate out for up to three weeks. The exhausting stint, which came to an end when just half of the on-site personnel were replaced by a team of volunteers on March 21, subjected workers to prolonged radioactive exposure.

Ukraine’s local nuclear authorities have criticized Russia for its dangerous behavior in seizing the defunct nuclear reactor. According to Reuters, workers at the Chernobyl site called Russia’s military operations in the area “suicidal,” since Russian troops advanced on the plant by traveling through the Red Forest—a highly radioactive zone where even workers at the plant dare not go.

Convoys of Russian military trucks have reportedly kicked up radioactive dust from the earth, spreading toxic isotopes into the air. Ukraine’s state power company, Energoatom, says Russian troops suffered radiation poisoning "very quickly” after digging trenches in the ground surrounding the site of the 1986 meltdown.

The IAEA said it had “not been able to confirm reports of Russian forces receiving high doses of radiation” poisoning while operating in the area, but the watchdog is now working to send a support mission to Chernobyl.

This story was originally featured on Fortune.com