A Britain-based monitoring group reports that the Syrian Army and allied militias have retaken a town at the doorstep of Daraa, a contested city that lies between Damascus and the Jordan border.

The conquest opens several supply routes to Daraa, which is divided between government and opposition fighters, the Syrian Observatory for Human Rights says.

Daraa was the scene of some of the first protests against President Bashar Assad in 2011 and holds symbolic value in the narrative of the uprising that has since collapsed into a vicious civil war.

Syria's official news agency says the offensive on Atman, north of Daraa, scattered rebel forces — which it labels terrorists.

Troops advanced under the cover of heavy artillery bombardment and air power, the Observatory reports.