U.S. researchers say that Russia has relocated thousands of Ukrainian children to a network of sites in Russian-occupied areas of Ukraine and in Russia whose main goal is to "reeducate" the children to make them pro-Russian.
The researchers said in a report published on February 14 that they had identified 43 camps and other facilities where at least 6,000 Ukrainian children have been held.
"The primary purpose of the camp facilities we've identified appears to be political reeducation," Nathaniel Raymond, one of the researchers, said in a briefing to reporters.
The report also provides evidence of the Russian government's efforts to sever communication between the children and their relatives in Ukraine and to prevent the children's return to Ukraine. Some of the camps are thousands of kilometers away from the children's homes.
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The children included orphans and others who were in the care of Ukrainian state institutions before Russia launched its full-scale invasion nearly a year ago. They also included children with parents or clear familial guardianship and children whose custody was unclear or uncertain due to the war.
The report says some of the children taken from Ukraine were placed for adoption by Russian families or moved into foster care in Russia.
The report was produced by the Yale University School of Public Health's Humanitarian Research Lab as part of a State Department-backed project that has examined human rights violations and war crimes allegedly committed by Russia.
"The fact that these are transfers and deportations of children is unconscionable by any standard," the State Department said in a news release.
The State Department said the unlawful transfer and deportation of protected persons was a grave breach of the Fourth Geneva Convention on the protection of civilians and constitutes a war crime.
It demanded that Russia immediately halt forced transfers and deportations and return the children to their families or legal guardians. It also demanded that Russia provide registration lists of relocated and deported children and grant access for outside independent observers to the facilities.
The youngest child identified in the Russian program was just 4 months old, and some camps gave military training to children as young as 14, Raymond said. Researchers did not find evidence that those children were deployed in combat, he added.
Moscow has denied intentionally targeting civilians and has pushed back against previous claims that it had forcibly moved Ukrainians.