The Syrian army has seized a chunk of territory from rebels in the southwest, Syrian state media and a war monitor said on Tuesday, the first major government advance in an offensive near the Jordanian border.
Meanwhile two Israeli missiles hit near Damascus airport overnight, state news agency SANA and the Syrian Observatory for Human Rights war monitor said. An Israeli military spokesman declined to comment on the reports.
SANA said the missile strikes near Damascus international airport were a sign of support by Israel for the rebels in the southwest.
SANA and media outlets run by Damascus ally Hezbollah said the Syrian army had taken control of the town of Busra al-Harir and the nearby Laja area.
The capture of the area cut across an opposition-held finger of territory in northeastern Deraa province, where President Bashar al-Assad has pressed his assault despite U.S. warnings.
There was no statement from rebel groups about the government advances.
Syria's southwest region is strategically sensitive because of its proximity to the frontiers with both Jordan and the Israeli-occupied Golan Heights. The United States and Russia, Assad's most powerful ally, last year agreed a "de-escalation" zone in the area that has helped to contain the violence there.
The offensive has displaced thousands from their homes.
The United States has told Syrian rebel factions they should not expect military support to help resist the offensive, according to a copy of a message sent by Washington to the commanders of rebel Free Syrian Army groups in the area.
The United States has repeatedly warned Assad against violating the de-escalation zone, saying it would have serious repercussions and pledging "firm and appropriate measures."
The Observatory said the Israeli strikes targeted weapons depots and warehouses belonging to non-Syrian militias loyal to the Syrian government.