On 31 January, Russia and Ukraine conducted a prisoner exchange. Russia claimed that each side received 195 soldiers, but Volodymyr Zelensky said that 207 Ukrainian soldiers had been returned. This was the 50th exchange since Russia's invasion of Ukraine in February 2022, and the first such swap since the recent plane crash which Russia claimed had 65 Ukrainian prisoners of war on board. There are continuing doubts in Kyiv regarding this assertion, especially because no photographs have been released showing dozens of dead bodies. Both sides have called for an international investigation, and the details of the incident remain unverified. In another development, the International Court of Justice has ruled that Russia violated terrorism and anti-discrimination treaties: see