The Turkish missile strikes targeted a media center for the Kurdish forces and a radio broadcast station in the far eastern countryside of Syria's northeastern province of Hasakah, near the Iraqi borders, killing 22 Kurds.
On the Iraqi side of the borders, Turkish warplanes targeted the Sinjar area, leaving 28 people, according to the Syrian Observatory for Human Rights.
The UK-based watchdog group said the death toll could likely rise as there are around 26 of others between wounded and missing.
The Turkish animosity toward the Kurds has always been obvious, with Ankara repeatedly saying it will not allow the Kurds to have a strong presence in northern Syria, near the Turkish borders.
Meanwhile, the U.S. said it was concerned over the Turkish strikes, as they were not coordinated with the U.S.-led anti-terror coalition.
The U.S. has emerged as the main backer of the Kurdish fighters in northern Syria, supporting the group in their battles against the Syrian city of Raqqa, the de facto capital of the Islamic State group.
The Observatory said that at least five people were killed Tuesday by strikes believed to have been carried out by the U.S.-led coalition.
Local reports said the Syrian Foreign Ministry is expected to release a statement of condemnation regarding the Turkish attacks on the Kurds.
