Twelve men have been arrested over banners displayed at the match between Celtic and Linfield last month.
Celtic closed the Green Brigade section of their stadium for two games after Uefa charged the club over an alleged illicit banner and blocked stairways during the Champions League qualifying match with the Belfast team on July 19.
Police Scotland said 12 men, aged between 18 and 49, have now been arrested after a "proactive police investigation into banners and material displayed".
They have all been released on an undertaking to appear at Glasgow Sheriff Court later this month.
Celtic's partial stadium closure, thought to have affected 900 season-ticket holders in the safe-standing section of the ground, will be lifted after the match with Hearts on Saturday but the club said "a number of fans within this area remain suspended" while investigations continue.
