The motorized mountain bike(s) of Damascus

Back in december when walking through Damascus I ran into this mountain bike rigged up with small combustion engine:

Mountain bike fitted with a combustion engine on Khalid ibn al-Walid street in central Damascus

If you ask me this is quite a marvel of engineering and although I never spotted a second one during the 3 days that I spend in Damascus I am pretty certain that this is not a unique modification but rather one of many that are produced in some back alley workshop. If anyone has seen more of these or has additional information about these please do let me know…

Update (26 Februari 2017):I ran into the same design in Mexico City today.