[Brightcolours]

Looks as if you used a ("protective?") filter on the lens. My guess is that one of the elements of the lens itself is flat enough to have the same effect, as I trust you did not use a filter on that 24mm.

 

Can't find if the following image also has been taken with the IS USM version, and of course can't see if it was taken with a filter, but if it was without filter and the same lens:

https://www.flickr.com/photos/franzli/27...6/sizes/l/

 

We see green ghost lights above the real lights. What makes me think it might not be the same is the different residual colour (here green, in your image blue).

 

https://www.flickr.com/photos/al_st/1595...mmf28isusm

 

Shows a blue ghost light on the street.

 

https://www.flickr.com/photos/serumeiro/...mf28isusm/

 

I suspect that is a ghost light too.