Syria's army gained ground from rebels in the south on Tuesday, in what a monitoring group described as a large-scale offensive in the region backed by Lebanese Hezbollah fighters against insurgents which included members of al-Qaeda's Syrian wing.
The south is one of the last remaining areas where non-jihadist rebels fighting President Bashar al-Assad have a foothold. Just a short drive to Damascus, the area remains a risk to the Syrian leader, who has otherwise consolidated control over much of the west.
"The operation started two days ago and is very big," Rami Abdel-Rahman, head of the UK-based Syrian Observatory for Human Rights monitoring group, said on Tuesday.
Abdel-Rahman said the offensive aims to take a triangle of rebel-held territory from rural areas southwest of Damascus to Deraa city to Quneitra. Syrian media and rebel sources said on Tuesday that battles raged in several areas of southern Syria.