ICC has opened an investigation
"I have reviewed the Office's conclusions arising from the preliminary examination of the Situation in Ukraine, and have confirmed that there is a reasonable basis to proceed with opening an investigation. In particular, I am satisfied that there is a reasonable basis to believe that both alleged war crimes and crimes against humanity have been committed in Ukraine in relation to the events already assessed during the preliminary examination by the Office. Given the expansion of the conflict in recent days, it is my intention that this investigation will also encompass any new alleged crimes falling within the jurisdiction of my Office that are committed by any party to the conflict on any part of the territory of Ukraine."
ICC Prosecutor, Karim A.A. Khan QC
https://www.icc-cpi.int/Pages/item.a...tement-ukraine