When we arrived, people were already gathering in a manner that appeared to be partly organized, but mostly ad hoc. Most were lining the sides of the street, kept on the side walks by a light police presence.
The main part of the march was preceded by a procession of modified cars, but soon it was dominated by marchers carrying banners bearing their colours, and the names of their affiliated groups. These were interspersed with more vehicles, many of them modified to allow groups to assemble and ride on open platforms. Some of the riders would occasionally reach into bags they had brought with them and throw handfuls of small objects into the crowd - especially if they saw children.
Many of the grim-faced marchers carried instruments with them that were often as ungainly as they were loud. They used these to play the soundtrack of their march, keeping time for their steps with staccato blasts and the thud of drums. The police were ever present in the background.
As is often the case at events such as this, the police swept in after the marchers in force to clear the streets and maintain order. After a brief, potentially awkward stand-off with this young bystander, the situation was quietly defused when he picked up what appeared to be a piece of candy from the street and then stepped aside to allow the police to pass.
Apparently they call this a "homecoming parade" - a local tradition to welcome home participants in one of their athletic sports. It was all a bit surreal, but it ended happily enough for all involved.