Four members of the Syrian Democratic Forces (SDF) alliance have been killed in a bomb explosion in the northeastern province of Al Hasakah, Al Watan newspaper reported on Sunday, Trend reports citing Sputnik.
No terrorist group has claimed responsibility for the attack so far.
The areas in northeastern Syria are under the control of the SDF, a predominantly Kurdish militia that receives support from the US military.
In the meantime, the Turkish Defence Ministry announced that Ankara and Washington had agreed to establish a coordination centre for joint operations and to create "safe zone" in the northern part of Syria that would include territory between 30 and 40 km wide.
Special forces from the US-backed Syrian Democratic Forces (SDF), made up of an alliance of Arab and Kurdish fighters, inspect the Tabqa dam, on May 12, 2017, after it had been recaptured earlier this week along with the adjacent city.
It would be controlled by Turkey in coordination with the US, while Syrian Kurdish forces, considered terrorists by Ankara, have to leave the area and surrender their heavy weapons.
Damascus condemned the plan, calling it "flagrant aggression" by Turkey and the United States against the Syrian sovereignty.