Fans throwing bottles and coins are "destroying" the reputation of Scottish football and "a line has been crossed" too many times this season, says Celtic defender Kristoffer Ajer.
Ajer's team-mate Scott Sinclair was almost struck by a glass bottle thrown from the crowd during Saturday's Scottish Cup quarter-final with Hibs.
The Easter Road club have so far been unable to identify the culprit.
"If this bottle hit Sinclair, it could have caused severe injury," Ajer said.
"Hopefully some action will be taken because you can't sit and wait for the first really bad injury to happen before anything's done.
"I've always thought that Scottish fans are the best in the world in terms of creating an incredible atmosphere and fantastic noise. But a few fans are destroying the whole picture."
Hibernian manager Paul Heckingbottom echoed that sentiment, and acknowledged that the safety of the players is paramount.
The Leith club have said they will improve the CCTV at Easter Road after their current system failed to identify the fan who threw the bottle on Saturday.
"People can get carried away, I understand that. People may have been out for a few drinks before, I understand that. But there is still a way that you have to behave," Heckingbottom said.
"We want to get a grip of it. While we can appeal to people to behave themselves and be responsible, we also need to get better ways to identify people and enforce penalties and bans."
Former Celtic attacker Kris Commons on Sportsound
There should be a strict fine, certainly, but the severity of the Scott Sinclair one, for me, should lead to that stand being closed. As a supporter, if your team is being affected by someone throwing someone, you'll intervene. Are we waiting for something severe to happen to someone who is going out on the pitch to entertain? It's almost impossible to identify the individuals so you need to go for the clubs.
Dundee United manager Robbie Neilson on Sportsound
We have to highlight the punishment a lot more. We highlight the incident, but nobody really sees the punishment a few days later. We have to show other fans that this is what happens if you do it. Justice has to be seen to be done. We have to try and educate people as well.