The British-based Syrian Observatory for Human Rights says Syrian troops have shelled the southern city of Daraa, killing at least 15 people.

The Observatory says dozens of people were wounded in the early morning bombardment Saturday.

The deaths in Daraa come amid an international outcry over the killings of civilians Wednesday in an assault on the small village of Mazraat al-Qubeir.

The United Nations says its monitors gained access to the village Friday where they saw armored vehicle tracks around the village and homes damaged by rockets, grenades, and various weapons.

A U.N. statement says “blood was visible across the walls and floors” of some homes and the observers were hit by a “strong stench of burned flesh.”

Activists say at least 78 people, including women and children, were killed in Mazraat al-Qubeir.

The Syrian government blames unidentified “terrorists” for the massacre.

The observers had been trying to reach the village since Thursday, but had been shot at and prevented from entering.

Mazraat al-Qubeir is the latest massacre in Syria. At least 108 people, almost half of them children, were killed when forces attacked the town of Houla on May 25. The government denies any role in the slaughter.

International envoy and former U.N. secretary-general Kofi Annan says the “specter of all-out war” in Syria grows by the day.