Turkish jets bombed U.S.-backed Kurdish militants in Syria overnight — with each side offering vastly different figures on how many fighters were killed.
The NATO member's military said it killed between 160 and 200 Kurdish militants north of Aleppo, according to the Anadolu Agency, Turkey's state-run press service.
Warplanes dropped 26 bombs on 18 targets, including nine buildings being used as headquarters, shelters and an arsenal, Anadolu cited a military statement as stating.
But Mahmoud Barkhadan, a senior Kurdish commander, told The Associated Press that the death toll was far lower, putting it at no more than 10.
He said Turkish tanks had been shelling their positions since Wednesday and that the assault was joined by jets overnight. Barkhadan said around 20 of his fighters were injured.
The strikes came in Aleppo province, north of the embattled city, where the Kurds have been making advances against ISIS in recent days, the AP reported.
Both Turkey and the Kurdish militia, known as the People's Protection Units, or YPG, are fighting against ISIS in Syria. The Kurds and Syrian rebels also share a common enemy in Syrian President Bashar al-Assad.
But despite these shared goals in Syria's complex civil war, Turkey also sees the Kurds in Syria as a growing threat as the militants recapture territory from ISIS along the Syria-Turkey border.
Furthermore, Ankara views the Syrian Kurds as an extension of its own banned Kurdish militant group, the PKK, which it considers a terrorist organization.
This has caused friction between Turkey and its NATO ally the United States, which backs the Syrian Kurds as the most effective force battling ISIS.
In August, Turkey launched an assault with jets, tanks and artillery in Syria, targeting both ISIS and the Kurdish militants.