The men were pictured being hit across the back and legs with a wooden stick in a public square after ISIS' fanatical Islamic enforcers ruled the electric keyboard was 'offensive to Muslims'.
One of the pictures shows two keyboards smashed to pieces after raids thought to have taken place in Bujaq, a few miles to the east of Aleppo in Syria.
According to text posted along with the images on a file-sharing website, the musicians were punished with 90 lashes alongside a man caught impersonating a 'hisbah'.
Since taking control of large parts of Syria and Iraq last year ISIS claims to have formed a Caliphate in the Middle East, and has taken to enforcing strict Sharia law within its borders.
