On May 22, 2009 Pedro Hernandez took the following video in Mexico City while travelling on a bus (shown in a program by Jaime Maussan; the closed captions can be auto-translated).
From 2:58 in the zoomed section of the video you can see a yellow glowing object emit many small white objects in front and behind it.
From 3:15 you can see pairs of small white objects orbit around each other and then move about the sky independently.
This behavior seems very different from balloons ... Read even more