At least five people have been reported to have been killed in the attack which was detonated in the town of Gandura, where the first checkpoint of Operation Euphrates Shield is located.
A car bomb exploded on Thursday in Syria near the opposition-controlled town of Jarabulus killed at least five people.
Raed Salah from of the Syrian Civil Defence (White Helmets), said bomb technicians from local police affiliated with Free Syrian Army (FSA) were killed.
It happened while they were searching a vehicle.
The YPG, an affiliate of the PKK terrorist organisation, was reportedly behind the attack.
The car loaded with explosives had come from YPG-controlled Manbij city and targeted the Turkish-backed FSA in the Euphrates Shield Operation area.
The vehicle was reportedly detonated in the town of Gandura, where the first checkpoint of the operation is located.
Earlier on in a similar attack in Afrin, a civilian was killed and 20 others were injured. The attack was located in the Olive Branch Operation area.
The YPG is the armed wing of the PYD, which is the Syrian offshoot of the PKK.
In its more than 30-year terror campaign against Turkey, the PKK, listed as a terrorist organisation by Turkey, the US and the EU, has been responsible for the death of some 40,000 people, including women and children.