Deadly rocket attacks on the Ukrainian port city of Mariupol this weekend that “knowingly targeted civilians” violated international humanitarian law and could amount to war crimes, the U.N. political chief said Monday. Jeffrey Feltman told an emergency meeting of the U.N. Security Council that monitors from the Organization for Security and Cooperation in Europe who examined the craters reported that the rockets originated from territory controlled by pro-Russian rebel separatists. He said Satu