The UK said on Thursday that 45 Organization for Security and Co-operation in Europe (or OSCE) participating nations are invoking the OSCE's Moscow Mechanism. This will set up a mission of experts to look into potential rights abuses committed by Russian forces in Ukraine. Ukraine supports the invoking of the Moscow Mechanism, the UK mission to the OSCE said. 

The OSCE mission will establish the facts around issues including cases of possible war crimes and crimes against humanity, including deliberate and indiscriminate attacks against civilians, the US said. The OSCE mission of experts will collect and analyse information with a view to presenting it to accountability mechanisms, as well as international courts and tribunals, the UK said.