BEIRUT (AP) — Talks to cede the largest opposition holdout in southwestern Syria to the government have failed, triggering an intense overnight bombing campaign on the densely populated town that killed a dozen people and injured over a hundred, activists and rescuers said today.

Britain-based Syrian Observatory for Human Rights said an overnight ‘frenzied’ bombing campaign continued into today, with at least 350 missiles lobbed into Nawa and its surrounding areas. The Observatory said at least 12 were killed as rescuers struggled to get to the casualties.

Khaled Solh, head of the local Syrian civil defense known as White Helmets, said only one ambulance was able to access the town and civilians relied on their cars to bring out at least 150 injured. He said the only hospital in the town was struck in the overnight campaign, rendering it nonoperational. He said one of the last orthopedists in the town was killed in the strikes.

In less than a month, Syrian government forces backed by Russian air power have been able to seize control of most of Daraa province, including the eponymous provincial capital that was the cradle of the uprising against President Bashar Assad more than seven years ago.

They have stepped up their military offensive on the remaining opposition pockets in the southwestern region that includes Daraa and Quneitra provinces that straddle the border with Jordan and the frontier with the Israeli-occupied Golan Heights.