Celtic have announced they will close the "Green Brigade section" of their stadium for the next two matches after "serious incidents of unsafe behaviour" at their previous two home games.
The announcement comes a day after Celtic were hit with UEFA disciplinary charges over an alleged "illicit banner" and "blocked stairways" during their Champions League victory over Linfield on Wednesday night.
The club also expressed their frustration over a pyrotechnic display during the final game of last season against Hearts.
The decision will affect 900 season-ticket holders in the safe-standing section of the stadium which houses the Green Brigade ultras group.
The closure will affect next Wednesday's first leg of the Champions League third qualifying round against Rosenborg.
Celtic manager Brendan Rodgers described the sanction as a "wake-up call" to the Green Brigade after UEFA took action over a banner which portrayed an individual in a paramilitary uniform.
Rodgers said: "It's really disappointing that we are talking about stadium safety and paramilitary banners rather than our progress into the next round of Europe.
"The fans have a responsibility to behave in the stadium and I would urge everyone involved to see the damage this is causing to the club.
"Hopefully this is a wake-up call.
"The players thrive on the cauldron that the fans create at Celtic Park, but there are clearly boundaries that you can't step over.
"Everyone knows that pyrotechnics, unacceptable banners and ignoring stewards who are enforcing basic stadium safety measures are simply not on.
"I really hope that the fans take this on board. It would be a real shame if they forced the club to take more permanent action to ensure safety and protect the club's standing in European football, which is what we should all be aiming to promote."
Chief executive Peter Lawwell told the club's official website: "The behaviour of fans in the Green Brigade section of the ground at the matches against Hearts and Linfield was a serious safety risk, which has left us with no choice but to take decisive action to ensure safety within the stadium.
"There is no room for debate. The safety authorities and the football authorities make the rules. They also enforce the rules.
"If the rules are broken, Celtic will be punished again and again. There is no hiding place from these realities. Anyone who has Celtic's interests at heart must surely recognise them and behave accordingly.
"Every club which visits here says the atmosphere is incredible and that is something that we have worked very hard to support and encourage.
"We cannot understand why supporters who are capable of contributing so much that is positive to the club can be so reckless in doing it damage. In addition to the serious safety concerns, we face further UEFA disciplinary action.
"This is not a decision we have taken lightly, but the behaviour of fans in this section is posing a direct risk to the safe operation of the stadium and is also seriously tarnishing the club's hard-won reputation.
"Dialogue, engagement and communication with the Green Brigade have evidently failed at this time, given the behaviour experienced at these matches, and we are therefore left with no choice but to take action to ensure safety at the stadium.
"We hope that the action we are taking prompts recognition by those fans of the damage being done to the club and that we can resume meaningful engagement with them which would ensure a safe environment within that part of Celtic Park."
A lengthy club statement condemned the action of some fans in the Green Brigade section of the stadium.
It read: "The safe standing area of the stadium had been working very well until the final game of last season against Hearts, when large numbers of flares were smuggled into and set off under banners within the Green Brigade section.
"It was an incredibly irresponsible and co-ordinated action which could have had tragic consequences.
"The club understands that consideration was given to halting this crucial game because of the thick smoke, which was blowing across the stadium and into other sections of the support and posed a serious safety risk to all those in the stadium.
"The fire alarm was activated, resulting in the Scottish Fire and Rescue Service responding to the stadium.
"The Safety Advisory Group of Glasgow City Council, which licenses Celtic Park and comprises representatives from the Council, police, fire and rescue, the ambulance service and other statutory authorities, had an emergency meeting after that game and communicated their serious concerns to the club, which presented a risk to the renewal of the safety certificate necessary for the operation of the stadium and the capacity of the safe standing area. "
The statement continued: "The club has been working with the Safety Advisory Group towards a solution for this season, but the events at the match on Wednesday night, where there were further serious safety issues within the Green Brigade section, require the club to take immediate action to comply with its responsibilities under the applicable legislation.
"Safety of all supporters at Celtic Park is of paramount importance to the club.
"The safe operation of the safe standing area at Celtic Park requires effective communication and engagement with the supporters in that area. "Unfortunately, due to the events at the Hearts and Linfield matches, the club is not satisfied that the Green Brigade section can be operated safely at this time.
"The club will continue to investigate the events at the matches in question and to address the issues that arose.
"The club will seek to engage with the supporters in the Green Brigade section to re-establish the necessary communication and engagement to permit supporters to be readmitted to the section and for it to be operated safely, in consultation with the Safety Advisory Group.
"If that cannot be achieved, then the club will require to examine other options."
