In the context of the current conflict, many violations were reported to be committed by the Russian side.
Concretely, war crimes refer to the serious violations of international humanitarian law. They are now listed in Article 8 of the Rome Statute of the International Criminal Court, adopted in 1998. Some states are not subject to the Court's jurisdiction because they have not ratified the Statute (including Russia and Ukraine). However, all states agree upon the definition of war crimes - this definition is thus the reference tool in this area.