An ISIS statement says the six busts were found when the smuggler was stopped at a checkpoint. The issue was referred to an Islamic court, which ordered that they be destroyed and the man be whipped.
Photographs released by the group showed IS fighters destroying the busts with large hammers.
The Britain-based Syrian Observatory for Human Rights said on Friday it was unclear if the busts were authentic or if the militants destroyed fake busts as a cover for the ISIS group’s own antiquities smuggling.
In March, ISIS members in Iraq razed 3,000-year old Nimrod and bulldozed 2,000-year old Hatra — both UNESCO world heritage sites.