BEIRUT -- Syrian rebels ignited a new front Friday outside Damascus in the first significant fighting there since regime forces swept over the suburbs weeks ago.
The return of violence to the Damascus suburbs raises questions about how long troops can control areas before the fighting erupts again.
Although government forces have shown they can crush armed fighters, the regime has appeared unable to conduct major offensives in more than one place at a time.
That points to the likelihood that a conflict that is now a year old and is estimated to have killed more than 8,000 could grind on as it slides closer to a civil war.
Diplomatic efforts have so far brought no result, but U.N. envoy Kofi Annan told the Security Council in a briefing Friday that he was determined to continue his mission and would return to Damascus.
Tens of thousands of people held protests against the regime in many Syrian towns and cities after weekly Muslim prayers -- in the northern city of Aleppo, Syria's largest, to the central regions of Hama and Homs, and the southern province of Daraa.
Security forces opened fire on several demonstrations.
In other developments, four more Persian Gulf states reportedly were closing their embassies in Damascus.
The Saudi press agency reported that Kuwait, Oman, Qatar, and the United Arab Emirates -- members of the Saudi-dominated Gulf Cooperation Council -- had joined Saudi Arabia and Bahrain in announcing the closure of their embassies in Damascus.
In addition, Turkey urged all Turkish nationals in Syria to return home as soon as possible, warning that it would soon close the consular section of its Damascus embassy -- a possible prelude to closing the embassy itself.