BEIRUT (AP) — Syria state media and opposition activists say government troops are advancing on rebel-held areas in the country's southwestern region amid intense clashes in a widening offensive, shattering a U.S-backed truce.

State news agency SANA reported fierce clashes Saturday in the al-Lujat area, a rocky region in the eastern countryside of Daraa. It reported troops advancing from the adjacent Sweida province have seized two villages.

The Britain-based Syrian Observatory for Human Rights reported the government advances, saying they were accompanied by intense shelling and airstrikes.

A local media activist who goes by the name Abu Mahmoud al-Hourani said the clashes were an escalation in a widening offensive, but denied the rebels lost any territory.

Washington warned the offensive in the region bordering Jordan and Israeli-occupied Golan Heights risks widening the conflict.