Turkey, which has long criticised Syria for its harsh crackdown on dissent, is considering a buffer zone on its border to protect civilians fleeing the troubled country, experts say.
Turkish Prime Minister Recep Tayyip Erdogan warned Syrian President Bashar al-Assad on Monday that his days as leader were numbered and he cannot remain in power indefinitely through military force.
After reports that two buses carrying Turkish pilgrims came under attack in Syria, Erdogan said his one-time ally's defiant refusal to end the crackdown on protesters had increased the prospects of foreign intervention.
Siding with Western powers, Erdogan's conservative Islamist-rooted government has threatened economic sanctions and used ever more virulent verbal attacks against Damascus.
"We are opposed to any unilateral initiative or foreign intervention to speed up regime change" in Syria, a Turkish government official told AFP, but did not rule out "additional measures" to protect civilians if the regime of President Bashar al-Assad resorted to "massive atrocities".
In this case the Turkish army could create a buffer zone on the border between the two countries to avoid a mass influx from areas close to Turkey, like the northern city of Aleppo, wrote Radikal newspaper commentator Murat Yetkin.
But Turkish diplomats insist that such a step, should it be taken, would be "purely humanitarian".
According to Robert Fisk of the British newspaper Independent, Damascus is concerned that a risk buffer could be seen as a pretext by Syrian militias to act.
Syria fears that such zones could be turned into pockets of resistance against the Assad regime, he told the Vatan newspaper in Istanbul after visiting the country which has been rocked by protests since early this year.
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Turkey has accommodated about 7,000 opponents of Assad's regime in its Hatay province which borders Syria, after they fled the violence.
Among them is Riad al-Asaad, a Syrian army colonel who heads a group of army deserters that carries out attacks inside Syria.
Ankara has distanced itself from the group but has offered a sanctuary to the broad-based opposition Syrian National Councils.
Turkish Foreign Minister Ahmet Davutoglu has repeatedly said that an exodus of refugees and a civil war on Turkey's doorstep would be a nightmare scenario.
"It is practically sure that the regime of Bashar al-Assad is faltering. All assessments are made on the basis of this assumption. The faster the regime falls the better for Turkey," said Hurriyet editorialist Sedat Ergin, describing the prevailing sentiment in the foreign ministry in Ankara.
Some analysts, however, warn against Turkey's hawkish position.
"Why this zealousness? Turkey should not establish a buffer zone," said military analyst Armagan Kuloglu, who accuses Ankara of tempting Damascus to play the Kurdish card and give free rein to the separatist PKK.
Deadly clashes between the PKK, or Kurdistan Workers' Party, and Turkey's army, a common phenomenon over the past decade, have escalated since mid-2011.
Turkey, like Iraq, Iran and Syria, is home to a large Kurdish minority.
In 1998, Turkey had threatened Syria with war if it continued to grant asylum to PKK leader Abdullah Ocalan, who was then wanted by Turkish authorities.
Ocalan was eventually arrested and jailed for life in 1999.
Listed as a terrorist organisation by Turkey and much of the international community, the PKK took up arms for Kurdish independence in southeastern Turkey in 1984, sparking a conflict that has claimed some 45,000 lives.