(The Hill) — U.S. researchers said at least 6,000 Ukrainian children have been “systematically relocated” to Russian camps with a focus on “re-education efforts” since the war with Ukraine began last February, according to a new report released on Tuesday.

The Conflict Observatory — a State Department-backed program that is collecting evidence of alleged Russian war crimes and atrocities in Ukraine — said that one of its partners, the Yale University Humanitarian Research Lab, had identified at least 43 facilities that are being used to hold Ukrainian children. 

The report said that the facilities, the vast majority of which previously served as Russian summer camps, appear to be primarily aimed at the “systematic re-education” of Ukrainian children.

“Multiple camps endorsed by the Russian Federation are advertised as ‘integration programs,’ with the apparent goal of integrating children from Ukraine into the Russian government’s vision of national culture, history, and society,” the report noted.

At least two of the camps have placed Ukrainian children who are allegedly orphans with foster families in Russia, and at least four others have suspended the children’s return to their families in Ukraine.

A State Department spokesperson said in a statement on Tuesday that the report’s findings represent a “grave breach” of the Geneva Convention and constitute a war crime.

“The fact that these are transfers and deportations of children is unconscionable by any standard,” the spokesperson said. “Russia must immediately halt forced transfers and deportations and return the children to their families or legal guardians.”