United Nations peace observers discovered 13 bodies Wednesday with their hands tied behind their back, which officials said is a clear sign they were executed. The findings are another sign of the growing violence in Syria. Maj. Gen. Robert Wood, the chief U.N. observer, said he was “deeply disturbed” by the “appalling and inexcusable act” after the bodies were located in the eastern province of Deir al-Zour. Wood did not pin the killings to either side of the conflict, saying that all should “exercise restraint” to “end the cycle of violence.” As world leaders called for action, Russia and China blocked a U.N.-sponsored intervention. U.S. Ambassador to the U.N. Susan Rice warned of a failed peace plan, saying violence could spread across the region, adding that Syria had “blatantly violated” peace commitments.