They can be towed but there are a couple of things that you need to do depending on how your towing.
The first one is you must of course ensure you do not exceed the maxium norma speed of the motor which is about 60-65mph I'd keep it to around 50mph to be on the safe side, if you do exceed it then you could end up with the motor exploding
Also select N with the gearlever, if you are towing with a A frame then you'll need to have the ignition on to unlock the steering of course.
Dont try to recharge the pack mind you by towing it and using the regen, while this may well work you could end up charging them @ 200Amps odd
and they wont really want that also there would be no management on the battery as such so you wouldnt really know whats going on.
So yes you can tow a Blingo if you need to get it home if its run out of juice
ChrisB