Hamilton police have charged a man they describe as the operator of a local anarchist group in connection with vandalism in the city's downtown last month.

Investigators have said that on March 3, a group of about 30 people damaged vehicles and threw rocks at store windows while carrying a large banner that read "we are the ungovernables."

Police also said they received evidence linking an anarchist book fair to the incident.

The incident caused about $100,000 in damage primarily to independent shops and cafes on Hamilton's Locke Street.

Hamilton police Deputy Chief Dan Kinsella says the 31-year-old man arrested and charged is believed to be the operator of The Tower, an anarchist collective.

Peter Hopperton, of Hamilton, faces a charge of one count of conspiracy to commit an indictable offence.