A U.N. investigation into the Israeli-Palestinian conflict in Gaza has found evidence that both sides committed "war crimes."

The United Nations says the investigation led by former South African judge Richard Goldstone concluded that "Israel committed actions amounting to war crimes, possibly crimes against humanity," during its Dec. 27-Jan. 18 military operations in the Palestinian territories.

The global body said the report released Tuesday "concludes there is also evidence that Palestinian armed groups committed war crimes, as well as possibly crimes against humanity," by firing rockets into southern Israel.

Israel refused to cooperate with the investigation, saying the U.N. Human Rights Council that ordered it was biased against the Jewish state.