Syrian Kurds push ahead in their offensive toward Raqqa

This frame grab from video provided by Qasioun a Syrian opposition media outlet, shows U.S.-backed fighters taking a rest during fighting with the Islamic State group near Ein Issa, north of Raqqa, Syria. Backed by U.S. airstrikes, Kurdish-led Syrian fighters clashed on Monday with Islamic State militants north of the city of Raqqa in Syria as they pushed ahead in their offensive aiming to liberate the city that has been the de facto capital of the extremist group since 2014. (Qasioun a Syrian Opposition Media Outlet, via AP) (The Associated Press)

This frame grab from video provided by Qasioun a Syrian opposition media outlet, shows smoke rising as a result of clashes between U.S.-backed forces and the Islamic State group, near Ein Issa, north of Raqqa, Syria. Backed by U.S. airstrikes, Kurdish-led Syrian fighters clashed on Monday with Islamic State militants north of the city of Raqqa in Syria as they pushed ahead in their offensive aiming to liberate the city that has been the de facto capital of the extremist group since 2014. (Qasioun a Syrian Opposition Media Outlet, via AP) (The Associated Press)

This frame grab from a video provided by Qasioun a Syrian opposition media outlet, shows U.S.-backed Syrian Democratic Forces fighters stationed near Ein Issa, north of Raqqa, Syria. Backed by U.S. airstrikes, Kurdish-led Syrian fighters clashed on Monday with Islamic State militants north of the city of Raqqa in Syria as they pushed ahead in their offensive aiming to liberate the city that has been the de facto capital of the extremist group since 2014. (Qasioun a Syrian Opposition Media Outlet, via AP) (The Associated Press)