Meta says its automated content-tracking system briefly blocked Facebook and Instagram hashtags about the apparent massacre in Bucha, Ukraine

• Meta's automated content-tracking system temporarily blocked the hashtags #bucha and #buchamassacre.
• The company said the system detected graphic content about the killings in Bucha, Ukraine.

Meta's automated content-scanning system blocked Facebook and Instagram hashtags related to the apparent massacre in Bucha, Ukraine, the company said.

The hashtags #bucha and #buchamassacre were temporarily blocked Monday when the system detected violent imagery, Meta spokesperson Andy Stone said.

Stone said on Twitter: "This happened automatically because of the graphic content people posted using these hashtags. When we were made aware of the issue yesterday, we acted quickly to unblock the hashtags."

The remains of hundreds of Ukrainian citizens have been unearthed in Bucha, a suburb of Kyiv, which spent weeks under Russian military control. US President Joe Biden on Monday called for a war crimes trial against Russian President Vladimir Putin over the apparent massacre in Bucha.

Meta has in the past come under fire from human rights groups such as Human Rights Watch and Amnesty International for deleting content that can serve as evidence of war crimes or human rights abuses.

Stone told Reuters that Meta was "exploring ways to preserve this type and other types of content when we remove it."

Meta said it did not have any further comment.