The Syrian Observatory for Human Rights said Turkish artillery struck areas of Aleppo, including Minnigh airbase recently taken by the Kurdish People's Protection Units (YPG) militia from Islamist rebels.
Ankara considers the Syrian Kurdish Democratic Union Party (PYD) and its YPG militia to be branches of the Kurdistan Workers Party (PKK) which has waged a decades-long insurgency against the Turkish state.
The shelling came shortly after Turkish Prime Minister Ahmet Davutoglu said Ankara would, if necessary, take military action against the PYD.
The premier was referring to Turkey's bombing campaign last year against PKK targets in their Qandil mountain stronghold in northern Iraq.
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A YPG source told AFP that the Turkish shelling targeted the strategic Minnigh airbase, which Kurdish forces retook late on Wednesday.
Turkey's Foreign Minister Mevlut Cavusoglu, quoted in Turkish newspapers, said Riyadh and Ankara were coordinating plans to intervene in Syria, where Russia has been backing a successful regime offensive against rebels.
"If there is a strategy (against the Islamic State jihadist group), then Turkey and Saudi Arabia could enter into a ground operation," he said.
"They (Saudi officials) came, did a reconnaissance of the base. At the moment it is not clear how many planes will come," Cavusoglu said.
Turkish media later quoted military sources as saying between eight and 10 Saudi jets would be deployed in Incirlik within the coming weeks, with 4 F-16 fighters to arrive in a first wave.
Asked if Saudi Arabia could send troops to the Turkish border to enter Syria, Cavusoglu said: "This is something that could be desired but there is no plan. Saudi Arabia is sending planes and they said 'If the necessary time comes for a ground operation then we could send soldiers'."
"If a decision is taken to send in special units against IS, Saudi Arabia is ready to take part.