Turkish defence ministry says at least 13 people killed in the Syrian town of Tal Abyad.
A humanitarian group has said one of its members from Myanmar working as a cameraman and medic has been killed by shelling in northeast Syria.
Turkish troops and their Syrian allies last month launched a cross-border operation into the region to drive away against Kurdish fighters seen as “terrorists” by Ankara.
In a video on Sunday, David Eubank, a former member of US Army Special Forces and the founder of the Free Burma Rangers, said the medic, Zau Seng, was hit in the head by shrapnel from a mortar shell that struck nearby as he was filming a video of clashes.
Eubank added that an Iraqi team member was also wounded in the mortar attack about four kilometres (three miles) from Tal Tamr, which he blamed on the “Free Syrian Army and Turks.”
“He died right away and we brought him here to Tal Tamr,” Eubank said in the video, which also showed one of the aid group’s armoured vehicles hit by shrapnel.
Turkey’s defence ministry, however, denied that Turkish troops attacked the aid convoy, saying that the reports “are not true.”
The Syrian Observatory for Human Rights, a Britain-based monitor with sources inside Syria, said the attack happened in a village called Rashidiyya.
A spokesman for the Syrian Democratic Forces, which is led by the Kurdish People’s Protection Units (YPG), said clashes were ongoing in surrounding areas.
Ankara considers the YPG an extension of the armed Kurdistan Workers Party (PKK), which has been fighting against the Turkish state for decades in demand of autonomy. Turkey, the US and the European Union consider the PKK a “terrorist” group.
Though a truce has mostly held, it has been marred by accusations of violations from both sides and occasional clashes.
Turkish President Recep Tayyip Erdogan has threatened to resume the offensive if deemed necessary.