Celtic boss Ronny Deila says the club's fans risk creating a "bad reputation" after flares were thrown during their 3-0 Scottish Cup win over Stranraer.
"We don't want this," Deila said. "It is something we need to get stopped.
"It is not positive for anybody and we don't want anything to do with it. Safety is the most important thing."
Celtic already have a Uefa charge pending after fans set off flares in their Europa League match with Fenerbahce in December.
The Scottish champions advanced to the fifth round thanks to two goals from Leigh Griffiths and one from Carlton Cole.
But Deila reserved his strongest post-match words for the behaviour of the fans, saying: "It's something that is making a bad reputation for the club.
"We've talked about it a lot and we have to get it away from this club.
"I don't know what kind of sanctions we could face, but it's important we follow the rules and that people are safe when they come to matches.
"That is why we have football as a cultural thing that everybody can be part of."