A protester kicks at police as they arrest a demonstrator Saturday morning in Vancouver. (CBC)Three people have been charged following a violent anti-Olympics demonstration in downtown Vancouver on Saturday.

Police say about 100 protesters, many dressed in black balaclavas and masks, broke away from a larger group and started smashing shop windows and vandalizing cars along West Georgia Street.

At a news conference in Vancouver on Sunday, the Vancouver Police Department described the group as a "criminal element" among the legitimate protesters.

Many activists who have been working for years on things like affordable housing in Vancouver's Downtown Eastside expressed dismay at the actions of those over the weekend.

"I was really disappointed. We've done a lot of work around protecting free speech," said David Eby with the B.C. Civil Liberties Association.

"If the feedback I've been getting from activists is any indication, they've not only turned off the public, but a large segment of the activist community with their tactics."

Protesters smash windows as they march through downtown Vancouver on Saturday morning. (CBC)Charlotte Christine Hannah, 23, of Vancouver and Willow Violet Louise Riley, 18, have been charged with assaulting a peace officer.

Daniel Frederick Myers, 22, of Washington state has been charged with possession of a dangerous weapon and possession of a prohibited weapon.

Police say he is being detained for immigration reasons.

"We're prepared for any eventualities," said VPD Const. Jana McGuinness. "We don't know for sure if these protesters will resurface."

McGuinness said these are initial charges and more people could be arrested and charged as police investigate Saturday's protest.