BEIRUT — Syrian and Russian forces launched a wave of airstrikes against rebel-held areas in the southwest and pushed into a major town on Thursday, resuming a wide-scale offensive after negotiations between Russia and the rebels collapsed.

The government’s advance in the southern Daraa province, which began on June 19, has captured wide areas and forced an estimated 330,000 people to flee their homes.

Opposition activists say scores of civilians have been killed.

State news agency SANA said Syrian troops entered the southern town of Saida after intense clashes with rebels.

The Britain-based Syrian Observatory for Human Rights reported some 600 airstrikes in Daraa province, including on rebel-held parts of the contested provincial capital of the same name.

associated press