In Syria, the Pentagon says a U.S.-led coalition airstrike in Tabqa killed 18 Syrian rebels backed by the United States. U.S. Central Command said in a statement the attack accidentally targeted fighters with the U.S.-supported SDF rebel alliance who requested air support in a fight against ISIS. CENTCOM offered condolences and called the deaths “tragic.” The attack followed a series of coalition raids that killed civilians. The journalistic monitoring group Airwars cited four separate U.S.-led airstrikes in April alone that killed 24 noncombatants.