VERYBODY fires rockets off, usually homemade bottle rockets made of straw and gunpowder (and often launched by hand). But the big event is the rocket contest, where each village comes out with a homemade rocket and see who's rocket flies the highest. These are literally tubes of 2" PVC, about 3' long, stuffed with gunpowder and a teak "nozzle" (a hole drilled into a plug of teak wood). Lots of explosives, mixed with lots of beer and local moonshine makes for a pretty fun time.
The spiraling rockets are new. I haven't seen them before this year. They aren't part of the contest, but part of the "opening ceremony" when they launch all sorts of cool rockets, usually linked by horizontal rockets flying along wires.