Hayat Tahrir al-Sham, whose name means Organization for the Liberation of the Levant, was the main rebel group leading the latest offensive, launching a surprise assault in late November from northwestern Syria that quickly led to the fall of President Bashar al-Assad. It is now leading the transition to a new Syrian government.

Video shows Syrian rebel fighters destroying tomb of the late president Hafez al-Assad, the father of the ousted Syrian president Bashar al-Assad. The tomb also houses the graves of Hafez al-Assad's wife and eldest son.

Israel has attacked Syrian military assets and has troops operating in the Golan buffer zone and slightly beyond.

Israel has attacked Syrian military assets and has troops operating in the Golan buffer zone and slightly beyond.

Bloomberg’s national security editor Nick Wadhams talks about some of the choices facing the US and other nations as a result of the turmoil in Syria (Source: Bloomberg)

Israel denied on Tuesday that its forces had penetrated into Syrian territory beyond the buffer zone with the Israeli-occupied Golan Heights, after Syrian sources said the incursion had extended to within 25 km (15 miles) of the capital Damascus.