Turkey on Monday became the latest country to close its embassy in Damascus, delivering a "strong political message" to the regime after a year of bloodshed in Syria.
A Turkish diplomatic source said the mission was closed because of deteriorating security conditions in Syria and that all diplomatic personnel had left Damascus.
"Activities at the Turkish embassy have been suspended from this morning," the source said on condition of anonymity, adding however that the consulate in the northern city of Aleppo will remain open.
Ankara has become increasingly strident in its criticism of its one-time ally over a brutal crackdown on protests in Syria that activists say has left more than 9,000 people dead since March last year.
"The closure of our embassy is obviously a strong political message (to the Damascus regime)," a source close to the Turkish government said.
Turkey has called on President Bashar al-Assad to step down and imposed a number of sanctions on Damascus, while emerging as the main haven for Syrian opposition groups.
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It is due to host a "Friends of Syria" conference in Istanbul on April 1 to pressure the Damascus regime following a first such meeting in Tunis last month attended by leading officials from Western and Arab countries.
Syrian opposition factions including the main Syrian National Council are meeting in Istanbul on Monday to prepare for the conference. The fragmented opposition has struggled to remain united in the face of the regime's deadly crackdown on dissent.
Turkey joins a number of other countries which have already closed their embassies in Damascus, including the United States, some EU members and the six Arab monarchies of the Gulf.
Foreign Minister Ahmet Davutoglu said last week that the survival of the Assad regime was "almost impossible".
"A regime fighting against its own people, trying to keep the status quo, cannot survive," he said in Vienna.
On Sunday, Russian President Dmitry Medvedev warned Syria that Kofi Annan represented the last chance for avoiding a civil war and offered the UN-Arab League envoy Moscow's full support.