At least five people died on Wednesday when a suicide bomber detonated himself at a local government office in Syrian town of Tel Abyad near the Turkish border.
According to witnesses, scores were wounded by the attack.
They said a suicide car bomber had attacked the building, which was captured by the YPG last year from Daesh terrorists in an offensive backed by U.S.-led air strikes.
The expansion of Kurdish influence in Syria is, a concern for Turkey, which considers PKK-linked PYD's takeover of Tal Abyad as a threat.
Thousands of Turkmens and Arabs who escaped from the PKK Syrian affiliate PYD, YPG in the northern Syrian town of Tal Abyad accused the organization of committing brutal offenses, including forcing people to migrate after confiscating their property and ethnic cleansing.
Tal Abyad lies north of Raqqa and had been a key supply line for the Daesh terrorist organization's so-called capital.