The U.S.-backed terrorist PKK/YPG dominated SDF forces killed at least 14 opposition fighters in northern Syria, activists said Monday.

According to opposition activists, SDF forces tried to infiltrate the opposition-controlled city of Tal Battal in northern Aleppo province, attacking positions.

The Britain-based opposition war monitor Syrian Observatory for Human Rights, said 14 opposition fighters were killed. According to the observatory, mines exploded during the attack that took place at dawn.

With artillery support, SDF fighters infiltrated the area, leaving "at least 14 dead" and others wounded in the attack, all pro-Turkish fighters, Observatory chief Rami Abdel Rahman reported.

The groups had been fighting over "control and influence" when the ambush happened, Abdel Rahman said.

The factional leader in the opposition-held area confirmed the death toll but told AFP the fighters were from a formation that had defected from pro-Turkish groups.

The SDF is dominated by the YPG, which is the Syrian wing of the PKK, recognized as a terrorist group by the U.S., Türkiye and the EU. The SDF has been the main partner of the U.S. in Syria and has driven Daesh out of the country's north and east over the last four years.

Taking advantage of the power vacuum created by the Syrian Civil War since 2011, YPG/PKK terrorists invaded several Syrian provinces, including Deir al-Zour, with the help of Washington under the guise of SDF. The terrorists forced many locals to migrate, bringing in their militants to change the regional demographic.

However, local tribes have been fighting against the YPG/PKK's oppressive policies, including arbitrary arrests and kidnappings. The YPG/PKK assassinated tribe leaders to yoke local groups.