The director of an anti-sectarianism charity has slammed the behaviour of a group of people who sang that they hoped Brendan Rodgers would be murdered by the IRA.
Lisburn man David Scott, from Scottish organisation Nil By Mouth, said the comments were "moronic and bigoted".
He spoke after a group of individuals, some of whom were wearing Celtic Football Club clothing, were captured on video in a pub singing that they hope Rodgers takes "a bullet from the IRA".
The incident reportedly took place in an Edinburgh bar.
It followed Tuesday's announcement that Rodgers had left the managerial job at Celtic to take over at Leicester City.
Yesterday, Police Scotland said they were "aware of footage posted to social media taken in a premises prior to the fixture between Hearts and Celtic on Wednesday night and will review this to establish if further action is required".
During the game at Tynecastle, which Celtic won 2-1, some Hoops fans turned on their former manager.
Mr Scott said the behaviour on display in the video "reflects appallingly on those involved".
"It's an utterly crass and moronic bit of behaviour, there's absolutely no excuse for it," he said.
"It's sadly typical of some of the complete and utter lunacy around Scottish football, where a guy who 24 hours earlier was a hero is subjugated to this sort of garbage.
"It reflects appallingly on the people involved.
"The majority of people who go to watch football in Scotland don't share their views."
He added that many in Scotland "don't have any idea" of the impact of the Troubles on Northern Ireland.
"I think you are dealing with people who view Northern Ireland from a distance and I don't think they have any sense of consequences," he added.
"Brendan Rodgers lived through the Troubles, but most of those people have no understanding of that period.
"It is bigoted behaviour - there is voyeurism around the IRA and people have no understanding of the reality.
"They don't realise the complexities."
Mr Scott said that the video was "one of a number of incidents in Scottish football in recent weeks".
Earlier this month, Kilmarnock manager Steve Clarke claimed he had received verbal abuse from Rangers fans at Ibrox, and Kilmarnock striker Kris Boyd was hit by a coin and claimed he was subjected to verbal abuse.
Mr Scott called for those responsible for the video relating to Brendan Rodgers to face "serious consequences", but said their behaviour wasn't the fault of football clubs.
Scottish Football Association chief executive Ian Maxwell said that his organisation "condemns in the strongest possible terms the spate of incidents this season involving unacceptable conduct in Scottish football".
He said: "This season we have witnessed match officials and players hit by coins, sectarian singing at matches and abusive and threatening behaviour towards match officials, players, managers and coaching staff.
"This behaviour is completely unacceptable and simply has no place in football, or indeed Scottish society. Football has a responsibility to take action.
"We must do all that we can under our current rules and engage with clubs to seek to eradicate such behaviour."
Mr Maxwell said he and Scottish Professional Football League (SPFL) chief executive Neil Doncaster had met with Cabinet Secretary for Justice Humza Yousaf, Minister for Public Health, Sport and Wellbeing Joe Fitzpatrick and Police Scotland assistant Chief Constable Bernie Higgins to discuss how to address unacceptable conduct in football. Leicester City Football Club declined to comment when approached by the Belfast Telegraph.
No response had been received from Celtic Football Club at the time of going to press.
In a statement after the incident involving Steve Clarke at Ibrox, Mr Doncaster said his organisation condemned "all unacceptable conduct and are fully committed to working with our clubs, th e Scottish FA, Police Scotland and the Scottish Government towards preventing such incidents at SPFL matches and responding appropriately where they do occur".
He added: "We and our member clubs have already taken significant steps in this area and will continue to play our part in helping to tackle this wider, societal problem."