It's even difficult to classify what they are, only because one word doesn't seem to cover it. It's a Brazilian martial art. The definition I found on the website of the group in the pictures calls it:
"a Brazilian movement form that incorporates martial arts, dance, and song with acrobatics, cleverness, and cunning. It is a dynamic physical and cultural form of expression open to all."
When it says "open to all," they mean it. Men mixed it up with women, adults with kids. Everyone took turns singing and playing instruments.
The video and sound I mentioned last time? That's not working out quite as I'd like it. My editing skills aren't quite ready for prime time yet. I'm working on it.