It was not clear if the aircraft had carried out any bombing in the area.
Syrian government warplanes were again in the air over the mainly Kurdish-held city of Hasakeh today despite a US warning against any new strikes that might endanger its military advisers, a monitor said.
It was not immediately clear whether the aircraft, which were in the skies throughout the night, had carried out any bombing runs as there were heavy artillery exchanges on the ground, the Syrian Observatory for Human Rights said.
Deadly clashes erupted between pro-government militia and the US-backed Kurdish forces on Wednesday. The following day, the regime launched its first ever air strikes against the Kurds.
The unprecedented strikes against six Kurdish positions in the northeastern city prompted the US-led coalition to scramble aircraft to protect US special operations forces advisers deployed with the Kurdish forces.
It was the first time the coalition had confirmed deploying warplanes against the Syrian air force.