A Facebook group that has emerged as the motor of unprecedented protests in Syria called for "popular uprisings" in all cities Saturday, as reports of killings in clashes continue to surface.

"Today, Saturday... popular uprisings in all Syrian governorates," read a posting on The Syria Revolution 2011, which has garnered the support of over 86,000 fans.

The "main goal" of the Facebook group, which has pages in English and Arabic featuring videos of protests and scenes of police brutality, is "freedom in Syria" with postings stating the "intifada against injustice has begun."

The call for fresh protest in Syria, which has been ruled by the Baath party for close to 50 years, came one day after at least 13 people, including two firemen, were killed in clashes between demonstrators and security forces in Homs, the southern town of Sanamen and a Damascus suburb.

An unnamed Syrian official put Friday's toll at 13, but activists said at least 25 people were killed on the Muslim day of prayer and rest.

Protests demanding major change spread across Syria on Friday despite an official announcement of a series of reforms, including the release of all activists detained this month and plans to "study" ending emergency rule which has been in place since 1963.

The southern tribal town of Daraa, near Syria's border with Jordan, has emerged as the hub of the protests and has sustained the most casualties.