Energoatom, the state enterprise overseeing Ukraine’s nuclear power plants, said Thursday that Russian forces had withdrawn from Chernobyl, the site of the world’s worst nuclear disaster in 1986.

The Chernobyl nuclear power plant and its surrounding territory fell into the hands of Russian troops in the first week of the war in Ukraine. In a statement on Telegram, Energoatom said: “It was confirmed that the occupiers, who seized the Chernobyl nuclear power plant and other facilities in the Exclusion Zone, marched in two columns towards the Ukrainian border with the Republic of Belarus.”

The statement added that Russian troops announced their intention to leave and hand over control to Ukrainian personnel on Thursday. Energoatom posted the copy of a formal letter purportedly signed by a representative of Russia’s National Guard, a representative of Russia’s state nuclear energy company Rosatom and a Chernobyl plant shift manager, with the heading “The act of acceptance and transfer of protection of the Chernobyl nuclear power plant.”

The letter states that “the administration of the protected facility makes no claims in relation to the troops of the National Guard of the Russian Federation.”

The Telegram statement from Energoatom said that a small number of “rashists” — a Ukrainian slur for Russians that combines the words “fascist” and “racist” — remained at the station.

“It should be noted that the information about fortifications and trenches that the rashists built right in the Red Forest, the most polluted in the entire Exclusion Zone, was also confirmed,” Energoatom said. “So it is not surprising that the occupiers received significant doses of radiation and panicked at the first sign of illness. And it manifested itself very quickly. As a result, almost a riot broke out among the military, and they began to gather from there.”

Separately, Energoatom said there were reports that a column of Russian soldiers who had encircled the town of Slavutych, which was built to house workers at Chernobyl, were also forming up to withdraw toward Belarus.

The US is also seeing Russian forces “drawing down” from Chernobyl and from the north and northwest of Kyiv, a senior US defense official told reporters Thursday.

The US believes Russian forces have likely “abandoned Hostomel airport,” also known as Antonov International Airport, outside of Kyiv to the northwest, the official said.