Looks like a balloon to me. Possibly tethered since it didn't move.
Considering all the drug trafficking going on in Ciudad, as mentioned, the balloon could be a survey drone of sorts, but, I'm guessing there's higher
probability it may very well be a something belonging to those participating in illegal activity; a signal, or a poor-man's cheap and expendable
balloon drone to give greater line of sight over territory against infringement by the law.
Edit: oops, Thank you Gortex for repairing us on the date/location!
edit on 9-8-2012 by Druscilla because: (no reason given)