The US-allied Syrian Democratic Forces (SDF) said five of its fighters had been killed on Saturday in attacks by Turkish-backed forces on the city of Manbij in northern Syria.
Fighting in Manbij broke out after Bashar al-Assad was toppled nearly two weeks ago, with Turkey and the Syrian armed groups it supports seizing control of the city from the Kurdish-led SDF on December 9.
The SDF is spearheaded by the YPG, a group that Ankara sees as an extension of the Kurdistan Workers Party (PKK) who have fought the Turkish state for 40 years.
Turkey regards the PKK, YPG and SDF as terrorist groups.
The United States has been mediating to stop fighting between Turkey and the Syrian Arab groups it supports, and the SDF.
The US State Department said on Wednesday a ceasefire around Manbij had been extended until the end of the week, but a Turkish defence ministry official said a day later there was no talk of a ceasefire deal with the SDF.
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