The video above shows police as they close in on Occupy San Francisco protesters on Saturday, but San Francisco police say what may not be widely available on video is the protesters' actions beforehand.
"The protesters threw zip-locked bags of paint, some contained bags of rocks," said San Francisco police spokesman Gordon Shy. "There was definitely intent to injure."
In the video, San Francisco police arrest protesters on California and Battery streets. It was shot by Jacob Crawford, a filmmaker who documents police action. The group was protesting the war in Afghanistan as it marks 11 years of bombs and bloodshed.
"The cops were hitting people with batons and shoving batons into people and slamming people around," Crawford said.
San Francisco police admit there were "a few incidents" in which officers used batons or police holds to make arrests.
Police circled and detained the protestors in the roadway at California and Battery streets, and the protestors allegedly threw flares and bags of paint at officers, some of which contained rocks.
Some protestors also fled to Pine and Sansome streets, and were detained there.
In total, police made 22 arrests, on charges including conspiracy, riot, refusing to obey a lawful order from a peace officer and resisting delaying and obstructing a police officer, and assault and battery on a police officer.
Searches of the protestors' backpacks turned up items including hammers, an ice pick, flares and other weapons and bags of paint containing rocks.
No word yet on injured protesters, or if those arrested have been released from jail yet. Updates as they become available.