International Criminal Court (ICC) chief prosecutor, Karim Khan, announced Monday that he would open an investigation into the situation in Ukraine.

In light of Ukraine’s acceptance of the ICC’s jurisdiction on an open-ended basis to address alleged crimes committed in its territory since 2014, Khan said the ICC could choose to exercise jurisdiction despite Ukraine not being a State Party to the Rome Statute.

On reviewing the preliminary examination by the Office of the Prosecutor, which determines whether a situation meets the Rome Statute legal criteria to warrant investigation, Khan affirmed  that there is a reasonable basis to proceed with an investigation of alleged war crimes and crimes against humanity committed in Ukraine.

According to Khan, the Office of the Prosecutor will next obtain authorisation from the Pre-Trial Chamber of the ICC to open an investigation. Alternately, the matter may be expedited if an ICC State Party were to refer the situation to the Office, which would allow an independent and objective investigation to commence immediately.

Khan called upon the States Parties and the international community as a whole to support the Office’s investigation. The Office will need additional budgetary support, voluntary contributions and gratis personnel for a swift investigation.

On Friday, Khan acknowledged the ICC’s jurisdiction over possible war crimes in Ukraine. He explained that the ICC has jurisdiction over “any act of genocide, crime against humanity or war crime committed within the territory of Ukraine since 20 February 2014.” He also clarified that the the crime of aggression amendment to the Rome Statute would not be applicable to the Russian invasion as “neither Ukraine nor the Russian Federation are State Parties to the Rome Statute.”

After months of mounting tensions, Russian forces invaded Ukraine from the north, east and south. Russian missiles bombarded cities and military bases. Russia has also seized control of the Chernobyl plant. Air raid warning sirens have been echoing throughout Ukraine forcing Ukrainians to flee to shelters and to borders to escape for safety. Ukraine’s Ministry of Interior has reported 352 civilian casualties in the attacks.