A day after Miami's police chief banned officers from carrying guns into City Hall, the police union fired back, challenging the rule as a violation of federal law and officers' rights, reports the Miami Herald.

The Fraternal Order of Police's attorney fired off an email to city officials Wednesday challenging the new rule that bans all officers, whether on duty or off, from carrying their guns into city commission or board meetings unless they are responding to a call or assigned to City Hall.

The union is demanding to bargain over the new rule and how it's carried out.

Union members believe the policy is retaliation for a February protest at City Hall during which officers flooded the commission chambers demanding that cuts to their benefits be restored.