Human rights activists recorded cases when Russians changed children's personal data to complicate the identification — Kateryna Rashevska, an expert at the Regional Centre for Human Rights

When taking children to the so-called "re-education camps," Russians added their age and then moved them to the territory of the temporarily occupied Crimea. 

"The child was kept there, unable to return, because according to their documents, he or she was no longer that child. There are also very young children who, because of their injuries, are simply unable to remember their names, and they can be called any name," Rashevska said.

The human rights activist says that 16,000 Ukrainian children deported to Russia have been identified, and 400 have been placed in Russian families.

"We have a problem with identification, and this is the first problem the state faces that needs to be solved," said Rashevska.