The Mardj-al-Sultan airbase is located in Douma, a town 18 kilometers from the capital. It served as a major stronghold for the Jaish al-Islam terrorist group.
Earlier, a source within the pro-government militia told RIA Novosti news agency that the Syrian army and militia had managed to establish a security zone around the airbase. Army engineers are demining the area.
The new alliance brings together Jaish al-Islam, the al-Nusra Front, Arhar al-Sham and other groups, led by Abu Khaled Islam and his next-in-command, Abu Bousam al-Barra.