The Syrian army and its allies seized control of a 30 km (19 mile) stretch of Syria's border with Jordan from rebels in an attack on Thursday, two rebel groups said.
A military media unit run by Hezbollah, a close ally of the Syrian government, said the army and its allies had gained control over all checkpoints and border posts on the border in Sweida, one of four Syrian provinces that border Jordan.
Rebel groups, some of them backed by Western and Arab states, still control much of Syria's southwestern frontier with Jordan and Israel.
Sweida province was not included in a US-Russian brokered ceasefire that took effect in nearby areas of the southwest in July.
Said Saef, spokesman for the Western-backed rebel group Martyr Ahmed Abdo brigade, said Thursday's attack came from two sides in Sweida's east countryside. "Most of the eastern Sweida countryside is now in the hands of the regime," he added.