The Free Syrian Army (FSA) has said that it will investigate allegations that its fighters mutilated the corpse of a female member of the YPG.
Barin Kobani is believed to have been a member of the all-female Kurdish Women's Protection Units (YPJ).
Videos seen by Al Jazeera appear to show FSA fighters standing over her body in a village near the Turkish border.
Kurdish news outlet Rudaw said that the video showed the woman's clothes had been partially removed, and parts of her body mutilated.
Rudaw said they could not independently verify the video.
Online, the Kurdish community shared photos of Kobani and expressed their outrage over her murder.
The Free Syrian Army has been fighting alongside Turkish troops in an operation against the Syrian Kurdish armed group YPG in the Syrian enclave of Afrin.
On Friday, at least two people were reportedly killed and 19 injured in attacks on Turkish towns near the border with Syria.
Turkey said the rockets were fired from a Kurdish enclave inside Syria. There have been more than two weeks of intense fighting in the area. Turkey considers the YPG a "terrorist" group.