MINNEAPOLIS, Minn. (CNN/KTTC) -- Clashes broke out Tuesday night during a protest over the death of a black man after his arrest by Minneapolis police.
Some protesters threw rocks at officers outside the city's third police precinct building. Some police vehicles were damaged.
Officers responded by firing a chemical dispersant.
The protest came after a video showed officers arresting George Floyd after a report of forgery on Monday.
The footage showed him pinned to the ground, with an officer's knee on his neck, while Floyd screamed that he could not breathe. The video clip was about 10 minutes long. It does not show the entire arrest process.
Police said Floyd resisted his arrest and appeared to suffer medical distress. He died later at the hospital.
Minneapolis Mayor Jacob Frey says the technique that the officer used is not allowed.
Police announced Tuesday that four officers were fired.
The FBI and Minnesota Bureau of Criminal Apprehension investigators are investigating.