In this file image posted on a Twitter account of Syria’s al-Qaida-linked Nusra Front early Tuesday, July 7, 2015, a fighter from the Nusra Front fires a weapon during clashes against the Syrian government forces at the western Zahra neighborhood in Aleppo, Syria. A group of U.S.-trained rebels that recently returned to Syria said Wednesday it has lost contact with one of its officer but is investigating reports that it has defected and handed over his weapons to al-Qaida affiliate in the country. (Al-Nusra Front via AP, File)
In this file image posted on a Twitter account of Syria’s al-Qaida-linked Nusra Front early Tuesday, July 7, 2015, a fighter from the Nusra Front fires a weapon during clashes against the Syrian government forces at the western Zahra neighborhood in Aleppo, Syria. A group of U.S.-trained rebels that recently returned to Syria said Wednesday it has lost contact with one of its officer but is investigating reports that it has defected and handed over his weapons to al-Qaida affiliate in the country. (Al-Nusra Front via AP, File) Uncredited Al-Nusra Front/AP
In this file image posted on a Twitter account of Syria’s al-Qaida-linked Nusra Front early Tuesday, July 7, 2015, a fighter from the Nusra Front fires a weapon during clashes against the Syrian government forces at the western Zahra neighborhood in Aleppo, Syria. A group of U.S.-trained rebels that recently returned to Syria said Wednesday it has lost contact with one of its officer but is investigating reports that it has defected and handed over his weapons to al-Qaida affiliate in the country. (Al-Nusra Front via AP, File) Uncredited Al-Nusra Front/AP