Turkey urged Syrian Kurds on Friday not to establish a break-away entity in northern Syria by force, with Prime Minister Tayyip Erdogan warning against any "wrong and dangerous" moves that could hurt Turkish security.
The warning was issued at a meeting in Istanbul between Turkish intelligence officials and Saleh Muslim, head of the Democratic Union Party (PYD), whose militias have been fighting for greater autonomy for Kurdish parts of northern Syria.
Muslim said last week that Kurdish groups aimed to set up an independent council to run Kurdish regions in Syria until the civil war ended. That would alarm Ankara, which is wary of deepening sectarian violence on its border.
Turkey is trying to hold together a delicate peace process with Kurdistan Workers' Party (PKK) militants on its own soil and is worried that moves towards Kurdish autonomy in Syria could embolden them and jeopardize that process.
"Necessary warnings will be made to them that these steps they're taking are wrong and dangerous," Erdogan told reporters, as members of his National Intelligence Agency met Muslim.
Separately, a Turkish farmer was killed and his two sons were wounded on Friday when a mortar shell from fighting between Kurds and Islamist rebels in Syria hit their field near the border, officials at the local state hospital told Reuters.
The incident in the Turkish border town of Ceylanpinar underscores fears that Syria's civil war, now in its third year, is dragging in neighboring states.
Last week Turkish troops returned fire and shot at PYD fighters after stray bullets from Syria killed a man and a 15-year-old boy in Ceylanpinar.
Turkey wants to extract assurances from the PYD that it will not threaten Turkey's security or seek an autonomous region in Syria through violence, and that it will maintain a stance of firm opposition to Syrian President Bashar al-Assad.
"We have three main expectations from Kurds in Syria. Firstly not to cooperate with the regime. When that happens, tensions between the Kurds and Arabs rise," Foreign Minister Ahmet Davutoglu told the Radikal newspaper.
"Two is not to establish a de-facto entity ... based on ethnic and sectarian lines without consulting with other groups," he was quoted as saying. "If such an entity is established, then all the groups would attempt to do the same thing and a war would be unavoidable."
His third expectation was that Kurds did not engage in activities that would "endanger Turkey's border security".
Muslim's meeting with the Turkish intelligence agency comes after a surge in violence on the Syrian side of the border.
The PYD captured the Syrian border town of Ras al-Ain last week after days of clashes with Islamist rebel fighters from the al-Qaeda linked Nusra Front.
Erdogan, who called a meeting of his military and intelligence chiefs as well as senior cabinet ministers on Wednesday to discuss the unrest, said they would come up with a plan soon to contain the violence.
"Our chief of staff, national intelligence agency and foreign ministry are working on this ... We will get together again and by discussing the developments over (the border) we will identify our steps and prepare a road map," he said.
Clashes between the PYD and rebels fighting Assad have flared since Kurds began asserting control over parts of northeast Syria from late last year. Turkish foreign ministry officials have met with the PYD twice over the past two months and have held "positive" discussions, a government source said.
The anti-Assad revolt has evolved from its origins as a peaceful protest movement in March 2011 into a civil war that has killed over 100,000 people and turned markedly sectarian.
Turkey has emerged as one of the strongest backers of the Syrian rebels, giving them shelter on its soil, but denies arming them. Along with its allies, Ankara has, however, tried to distance itself from hardline Islamist groups like Nusra.
"I view (their) behavior as a betrayal to the Syrian revolution," Davutoglu said, citing footage of killings and kidnappings carried out by radical groups.
"But we have always supported the legitimate Syrian opposition and we continue this support."
Syria's ethnic Kurdish minority has been alternately battling Assad's forces and the Islamist-dominated rebels. Kurds argue they support the revolt but rebels accuse them of making deals with the government in order to ensure their security and autonomy during the conflict.
Turkey meanwhile has been making gradual but fragile progress in its efforts to end a three-decade insurgency by the PKK in its southeast, a conflict which has killed some 40,000 people.
The PKK called a ceasefire this year but there has been a recent increase in militant activity and Kurdish politicians have voiced concern that the government has not been enacting promised reforms quickly enough.