Russia has probably committed crimes against humanity by forcibly transferring Ukrainian civilians in Russian-occupied areas of the country to other regions, Amnesty International said Thursday.
It said civilians were moved from occupied Ukraine further into Russian-controlled areas or into Russia, with children separated from their families in violation of international humanitarian law.
Amnesty said it had been told by civilians they had endured "abusive screening processes" -- known as filtration -- which sometimes resulted in arbitrary detention, torture and other ill-treatment.
"Separating children from their families and forcing people hundreds of kilometres from their homes are further proof of the severe suffering Russia's invasion has inflicted on Ukraine's civilians," said Agnes Callamard, Amnesty International's secretary general.
"Russia's deplorable tactic of forcible transfer and deportation is a war crime. Amnesty International believes this must be investigated as a crime against humanity," she said.
Amnesty said that in one case a woman was separated from her 11-year-old son during filtration, detained, and not reunited with him.
The rights group said it interviewed 88 people, the majority civilians from Mariupol, the Ukrainian Black Sea city seized by Russia after a brutal siege, as well as residents from the Kharkiv, Lugansk, Kherson and Zaporizhzhia regions.
"Most, especially those from Mariupol, described coercive conditions that meant that they had no meaningful choice but to go to Russia or other Russian-occupied areas," it said.
The transfers "amounted to war crimes and likely crimes against humanity," it said.
Amnesty said that once in Russia, several people said they felt pressured into applying for Russian citizenship, or said their movements were restricted.
The report is one of the most significant interventions by Amnesty over Russia's invasion of Ukraine since it angered Kyiv in August by publishing a report that accused Ukraine of endangering civilians by establishing bases in schools and hospitals.
The group at the time said it stood by the findings of the report, which prompted the head of Amnesty's Ukraine office to resign in protest, accusing the rights organisation of parroting Kremlin propaganda.
But it also acknowledged the "distress and anger" that the report had generated.
In its latest release, Amnesty emphasised that it had been documenting "war crimes and other violations of international humanitarian law committed during Russia's war of aggression in Ukraine since the conflict began" and has called for officials to face justice.