Prosecutors investigating war crimes cases in Ukraine are examining allegations of the forcible deportation of children to Russia since the invasion as they seek to build a genocide indictment, the country’s top prosecutor said in an interview.

International humanitarian law classifies the forced mass deportation of people during a conflict as a war crime. "Forcibly transferring children" in particular qualifies as genocide, the most serious of war crimes, under the 1948 Genocide Convention that outlawed the intent to destroy — in whole or in part — a national, ethnic, racial or religious group.

Prosecutor General Iryna Venediktova, who is overseeing multiple war crimes inquiries in Ukraine, said "we have more than 20 cases about forcible transfer of people" to Russia from various regions across the eastern European country since the invasion began on Feb. 24.