In Syria, Turkish officials are calling for an immediate ceasefire in the northwestern province of Idlib, warning that a Syrian and Russian assault on the country’s last major opposition-held enclave could create a catastrophe rivaling all others in the nearly eight-year conflict. Turkey’s call came as U.N. investigators said that U.S.-led forces may have carried out war crimes in Syria. In a report released Wednesday, the investigation found that during a U.S.-led assault on ISIS, “international coalition forces failed to employ the necessary precautions to discriminate adequately between military objectives and civilians.” The U.N. also found Russian and Syrian forces may have committed war crimes by intentionally targeting civilian sites, including hospitals and clinics, schools, farmland and markets.