Celtic have slammed a section of their fans after the club was hit with another UEFA charge following the use of pyrotechnics by supporters at last week's Europa League match against CFR Cluj at Celtic Park.
A spokesperson for the club confirmed that "further measures" will be introduced in a bid to deal with the behaviour.
The Hoops have been hit with several sanctions from European football's governing body in recent years relating to the behaviour of fans, and were punished for the actions of travelling supporters during the away leg of the Europa League play-off clash against AIK in Stockholm.
The latest incident relates to Celtic's 2-0 win over Cluj, where pyrotechnics could be seen in the section populated by the fans group calling themselves the "Green Brigade".
Uefa has announced that the Ladbrokes Premiership champions face a charge for "setting off fireworks" - a breach of the body's disciplinary regulations.
While a decision will be made on October 17 regarding punishment, the club has today issued a strongly-worded statement condemning the "small minority" who persist in breaking UEFA rules.
The statement read: "Following the latest UEFA charge against the club for the use of fireworks at Celtic Park, it is with real disappointment and frustration that the club needs to appeal again for this behaviour to stop.
"UEFA’s stance on the issue of pyrotechnics is unequivocal and very well-known.
"The club has been sanctioned on numerous occasions and yet, very disappointingly, this behaviour by a small minority persists. In addition, the numerous financial penalties placed on Celtic continue to come out the pockets of supporters who invest in the club."
Warning supporters that the club risks "further, very serious repercussions," the statement continues: "The club does not want it, our supporters do not want it and UEFA will continue to punish the club whenever it occurs as it is a clear breach of their regulations.
"Given the number of repeated offences, we should also be very aware that there could be further, very serious repercussions which could have hugely detrimental consequences for the club and our supporters."
The statement closes with a plea to fans to "work together [with the club] to make sure pyrotechnics and any other form of unsafe behaviour have no place at our matches."