Up to two and a half thousand Ukrainian soldiers who surrendered after spending weeks defending the Azovstal steel plant in Mariupol, are thought to be being held captive in Russian occupied areas of Donetsk - as Ukraine tries to negotiate their release.

Today, according to the Russian news agency TASS - two of their commanders were taken into Russia itself - to a detention centre in Moscow.

Pro-Russian officials in Donetsk have hinted at a so called "international tribunal". So what's happening to the other soldiers? Paul McNamara has been finding out.