Britons Aiden Aslin and Sean Benner and Moroccan Ibrahim Saadoun serve in the Ukrainian army. According to a video clip broadcast by pro-Russian social media channels, they were imprisoned in court on Tuesday. The defendants say they are ordinary soldiers who fought in the Ukrainian army. Therefore, they should be treated as prisoners of war.

The two British soldiers were taking part in the defense of Mariupol’s Azovstal steel plant when they were captured, according to the Guardian. Aslin, who previously volunteered to fight with a Kurdish militia against Islamic State fighters, has a popular Twitter account. Shows how he was sworn in in the Ukrainian armed forces.

The accused are the first Ukrainian soldiers to be tried by pro-Russian forces since the Russian invasion on February 24. Observers say the trial is intended, among other things, to force an exchange of Russian prisoners tried in Ukraine, the Guardian writes.

Ukraine has indicted three Russian soldiers for war crimes during the invasion. A soldier was sentenced to life imprisonment for the murder of a civilian. Two other soldiers were sentenced to more than 11 years in prison for bombing civilian targets.