British Columbia's main civil rights watchdog group did not send any legal observers to a violent protest in Vancouver this weekend because they were asked not to by an anti-Olympic group, the organization said Monday.

Three people, including one American citizen, were charged with assault and weapons offences after protesters smashed in windows at downtown businesses and vandalized cars during an anti-Olympic demonstration that turned violent Saturday morning.

BC Civil Liberties Association Executive Director David Eby said there were signs beforehand that the protest could turn violent but they didn't go because the Olympic Resistance Network requested legal observers stay clear of the march.

"They were concerned we were infiltrated by the police. The second concern is that the footage we took could be potentially used against them in court if the police obtained an order that would force us to disclose that."

Eby said the BCCLA made a decision to stay away to protect its legal observers – who are all volunteers -- over fears of civil disobedience.

"They're not police officers or security guards. We don't want to put them in a dangerous situation."

Eby said he anticipated the disobedience would be similar to APEC protests, where demonstrators sat down in the streets and created blockades.

"What we saw was something quite different -- a small group within that demonstration physically fighting with the police and that's not what we anticipated," he said.

"If that's the case we wouldn't have sent observers anyways because it was a very dangerous atmosphere."

He admitted the protesters actions have affected the BCCLA's credibility as a watchdog organization.

"I really wish we had been there because we don't have the footage and the photos we would have liked of the police response and how things went down," he said.

"We're not in a position to be as informed about what happened as we'd like to be."

Michael Vonn, policy director, praised police for their "light touch" with demonstrators at recent protests.