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Twitter will prohibit posts by governments and state-linked accounts that show prisoners of war captured during fighting in Ukraine.
Ukrainian government social media accounts have posted videos showing Russian prisoners of war answering questions or making phone calls home.
The Geneva Conventions – the internationally agreed rules of war – state that prisoners must be protected at all times “particularly against acts of violence or intimidation and against insults and public curiosity”.
Twitter's head of site integrity Yoel Roth said a new policy requiring the posts to be taken down would not be applied retroactively.
"We don't want Twitter to be used by state actors to infringe on international humanitarian law and, to the best of our ability, we want to disincentivise governments from engaging in this type of behaviour," he said.
The company said it would add a warning note to tweets where there was a “compelling public interest” in showing the content.
Human rights group Amnesty International last month called on the rights of prisoners to be respected after Russians were brought to news conferences to discuss their roles in the military invasion.
It said public appearances could jeopardise their safety when they eventually returned home or could cause problems for their families while they were detained.
“As the conflict continues, it is essential that all parties to the conflict fully respect the rights of prisoners of war,” said Joanne Mariner, director of Amnesty International’s Crisis Response Programme.
Moscow has throttled access to Twitter by slowing its service and has banned Meta's Facebook and Instagram.