Procession

Yesterday, on Saturday morning I was a witness to unknown procession in Old Town on Kalku iela.
People were carrying flag of Latvia and another one similar to Italy or Hungary, but flag holders were not looking like Italians nor Hungarians :)
Does anybody know what kind of parade it was?
People Reaction (3)
these are student corporations
http://bit.ly/dIUwIb
haven't you seen Aristotelis, which is held on dome square in september? they're marching there
According to the color, it could be "Selonija"
http://lv.wikipedia.org/wiki/Selonija
Thanks for your input, guys!
According to Wikipedia it seems to be celebration parade of Selonija 130th anniversary :)