Turkish and Russian patrol is seen near the town of Darbasiyah, Syria, Friday, Nov. 1, 2019.
Tal Abyad lies in a region that has seen some of the heaviest fighting since Turkey launched a military incursion against the YPG in northeast Syria last month, after the United States pulled its troops out from the region.
The Britain-based Syrian Observatory for Human Rights said it was part of an eastern stretch of the border where United States forces are seeking to maintain a presence.
Ankara views Syrian Kurdish fighters as "terrorists", and wants to expel them from areas along its southern border.
"Turkey is protecting not only its own borders, but also the borders of North Atlantic Treaty Organisation".
On Wednesday, President Tayyip Erdogan said Turkey had information that the YPG had not completed its pullout from the border region.
The patrols add to the complicated mix of forces operating along the frontier, including US troops who inspected an eastern section on Thursday for the first time since US President Donald Trump said last month his country was withdrawing.
But on Saturday, US troops visited Kurdish forces in Qamishli in the second such spotting of American forces in northeastern Syria since that announcement.
"We harshly condemn the inhumane attack of the bloody PKK/YPG terrorists who carried out a bomb attack against the innocent civilians of Tal Abyad who could return to their homes and lands as a result of Operation Peace Spring and we call on all countries to take a stand against this brutal terror group", the National Defense Ministry said in a written statement. Mazlum Abdi, also known as Kobani, told Italy's La Repubblica newspaper that future negotiations required guarantees from the global community, including Europe. In the current negotiations, Abdi said Russian Federation was acting as an intermediary between his group and the government of Syrian President Bashar al-Assad.
Abandoned by their ally Washington - which early last month pulled its own troops back from the border area, effectively allowing Turkey to attack - the Kurds turned to Damascus which swiftly deployed its forces, reclaiming swathes of territory it lost as long ago as 2012.
But the USA had partnered with the Syrian Kurdish fighters, their top allies in the war against the Islamic State group.