"Those Canadian citizens who came here, they came to kill us and they came to kill our kids and to destroy our towns," said a Syrian Democratic Forces spokesman.

A withdrawal by U.S. forces opened up a dangerous new phase in the region's eight-year-old conflict.

Canada's Foreign Affairs Minister Chrystia Freeland said the unilateral action by Turkey risks rolling back the progress against militants affiliated with the Islamic State, also known as Daesh.