Spokesman for U.S.-backed Syrian forces says troops have liberated Raqqa, the de facto capital of Islamic State militants. The city of Raqqa has been completely liberated from the Islamic State, the spokesman for a U.S.-backed force in Syria and the the Syrian Observatory for Human Rights activist group said Tuesday. It came after U.S.-backed, Kurdish-led forces captured the city hospital in Raqqa, formerly the the extremist group's de facto capital on Tuesday, leaving the militants holed up at the local stadium. Ref. USAToday.