Turkey and members of the Arab League have called for "urgent measures" to protect Syrian civilians from a brutal government crackdown.
At a meeting in Morocco, they also declared they were "against all foreign intervention in Syria".The statement came hours after reports that rebel Syrian troops had attacked a major military base near Damascus.
In another sign of Syria's increasing international isolation, France said it was withdrawing its ambassador.
Foreign Minister Alain Juppe told parliament: "There has been renewed violence in Syria, which has led me to close our consular offices in Aleppo and in Latakia as well as our cultural institutes and to recall our ambassador to Paris."
Although Turkey is not a member of the Arab League, its Foreign Minister Ahmet Davutoglu attended a meeting of a Turkish-Arab co-operation forum in the Moroccan capital Rabat on Wednesday.
Turkey, which shares a long border with Syria, has been increasingly critical of President Bashar al-Assad's repression of anti-government protests.
"The forum declares that it is necessary to stop the bloodshed and to spare Syrian citizens from new acts of violence and killing, and demands that urgent measures are taken to ensure the protection of civilians," a statement said.
"Ministers also stressed the importance of Syria's stability and unity and the need to find a resolution to the crisis without any foreign intervention."
Earlier, Mr Davutoglu told Arab League ministers that Syria faced isolation if it continued on its path.
"The cost for the Syrian administration of not fulfilling the promises it made to the Arab League is its isolation in the Arab world as well," he said.
"The Syrian regime should read well the message the Arab League is sending and it should stop violence against its own people to open the way for the inevitable democratic transformation."
President Assad is under increasing international pressure after failing to honour the terms of an Arab League peace plan.
The league is expected to ratify its vote last weekend to suspend Syria's membership, and to discuss possible further measures against Damascus.
However, as the talks took place in Rabat, angry supporters of President Assad attacked the Moroccan embassy in Damascus and stripped it of its flag, ambassador Mohammed Khassasi told AFP news agency.
Al-Arabiyah TV also reported attacks on the Qatari and United Arab Emirates' embassies in Syria.
Over the past week, several regional embassies in Damascus have been attacked following the Arab League's vote to suspend Syria.
Soldiers killed
Syrian activists say defected soldiers known as the Free Syrian Army launched a pre-dawn attack on the notorious Air Force Intelligence building in the Damascus suburb of Harasta.
Unconfirmed reports said six government soldiers were killed.
Correspondents says such an attack would be the highest profile operation so far by renegade troops.
The Commander of the Free Syrian Army, Ryad al-Asa'ad, who is based in Turkey, told the CA Arabic Service the international community had let them down in their fight against the regime.
"At the moment no country in the world has helped," he said."All of them, every country has refused. Even Turkey has never offered us even one bullet and has even completely banned operations on the border, or on the road to the border. On the other hand, we are from inside Syria, we work inside Syria and the weapons are from Syria."
He said defections were increasing within the Syrian army.
"Thank God, there is a big number [of defectors] the number increases daily. Now, over the past 10 days, defections have been increasing in a very very big way, even officers, a great number are defecting."
Meanwhile, anti-government activists reported further bloodshed across Syria on Wednesday.
The Local Co-ordination Committees (LCC) said 11 people had been killed in Homs, seven in Idlib and one each in Daraa and the suburbs of Damascus.
The London-based Syrian Observatory for Human Rights said on its Facebook page that three defectors and a civilian were shot dead in Keferzita, Hama province.
Some 376 people had been killed since the announcement of the Arab League initiative on 2 November, the LCC said.
The UN says more than 3,500 people have died since protests started in March. Syrian authorities blame the violence on armed gangs and militants.
The Syrian government has severely restricted access for foreign journalists, and reports are difficult to verify.
