Looks like there were some people at odds in this video. It took place during a public prayer, where these folks were just standing around praying out loud. Then some protesters or activists were there too. They all clashed. This took place at the St. Louis Statue in St. Louis City.
Sure enough, it turned into a fist fight and about three of the public prayer people got sorta beat up.
One guy got hit with his own stick in a move dubbed "the boomerang."
Cop Watch STL had all the details: