A Syrian opposition group is calling for international protection for civilians in the central city of Homs, a day after security forces carried out the latest deadly assault cracking down on anti-government protesters.

The Syrian National Council said Monday Homs is a “disaster area” and urged international and Arab observers to oversee the situation on the ground.

On Sunday, Syrian security forces killed at least 13 people, most in Homs, where activists say the military is conducting an ongoing campaign against the city.

The United Nations says the number of people killed during the uprising has topped 3,000.

The Syrian government has blamed much of the unrest on “terrorists” and gunmen.