LOS ANGELES—Occupy Los Angeles protesters say the city violated their constitutional rights when it evicted them from the City Hall park last year.

City News Service says the group's lawsuit, which was filed on Thursday and seeks class-action status, claims a police raid that resulted in nearly 300 arrests was an unlawful violation of rights to assembly, association, freedom from unlawful seizure and liberty.

The Occupy demonstrators, part of a nationwide anti-Wall Street social movement, took over the park for two months and they were ousted on Dec. 1, 2011 in what the lawsuit calls Police Department "shock and awe" military tactics.

Extra law enforcement, restoration of the property and other city expenses cost taxpayers more than $4 million.