Celtic have launched an investigation after fans aimed missiles at shaken players as they demanded the sacking of manager Neil Lennon.
The Parkhead boss is fighting for his job after a 2-0 home defeat to Ross County ended in a Betfred Cup exit.
Goals from Ross Stewart and Alex Iacovitti ended a 35 game unbeaten run in domestic cup competitions and earned the Dingwall side a place in the last eight.
The result sparked ugly scenes when a mob of around 200 supporters ignored coronavirus restrictions to gather outside the main stand. Online videos showed a group of yobs throwing missiles at the cars of players as they received an escort from the stadium.
Tight-lipped on the fate of the fate of their manager, Celtic issued a strongly worded statement attacking the actions of fans as the SPFL seek talks with the Scottish Government over a return to grounds for supporters.
Celtic have been at the forefront of calls to relax Covid-19 restrictions for football and Sunday's strongly worded statement read: 'Everyone at the Club is hugely disappointed by this afternoon's result, one which has ended our phenomenal run of 35 consecutive cup victories.
'While we sincerely share the huge disappointment of all Celtic supporters, there can be no excuse for some of the violent scenes at Celtic Park this evening. The club will be investigating these events fully.
'For players and a management team, who have given so much in recent years and have delivered 11 consecutive trophies, to require an escort from Celtic Park while being targeted with missiles, is simply unacceptable.
'While we understand that only a small number of people were involved in this behaviour, some of the actions this evening, which have obviously left our own players shaken, cannot be condoned in any way.'
As fans chanted for his dismissal Lennon claimed he could still turn around a dismal run of two wins in 10 games, insisting it was too soon for sack talk.
Fighting a losing battle for his job after another lacklustre display, however, Lennon said: 'I'm not going to answer any hypothetical questions, 'But I think it's too soon for that.
'We've lost one trophy, that's gone. Our priority, as we know, is the league. It always is every time we go into a new season.We are out of Europe and it's not been great but there is plenty of time to turn it around.
'But it's alright me saying that. We have to show it with action now. And I think I should get more time at it - but if not then so be it.'
Granted time to turn things around in the belief home games with Ross County, St Johnstone and Kilmarnock could spark a recovery, Lennon could even be sacked on Monday after making it clear he won't resign.
Due a year's salary as a pay-off if he goes he discussed his situation with major shareholder Dermot Desmond and Chief Executive Peter Lawwell on Friday.
Eleven points behind Rangers in the league Parkhead power brokers are short of viable alternatives, but may now feel they have to make a change to keep any hope of ten-in-a-row alive.
Facing the music afterwards Lennon added: 'Do I see myself as the man to lead the team? Of course.
'I believe in myself. I am not always going to harp on about what I have done in the past. We are in the present and I know the expectations from the supporters and the board for the club.
'I am falling short of that at the minute, me and my backroom team. It's okay saying, 'We are going to turn a corner'. There is no point talking about it - we need to do it with our actions and soon. Otherwise the landscape could change for me very quickly.
Asked if he expected the board to vow to pressure to make a change he shrugged: 'I can't answer that. But I spoke to Dermot and Peter on Friday and we want to find solutions to the problems we are having.
'On the evidence of today, we are still having those problems. I can't say what decisions the board may or may not make.
'I know it isn't good enough at the minute and I am not going to sit here like a happy clapper and say. 'Everything is positive, we can turn things around'.
'We know we need to work hard to do that. We had a really good meeting (with players) on Saturday. It was powerful and a lot of good stuff came out of it.
'There was a good ambience and atmosphere coming into the game but we just aren't making it happen at the moment.'
Despite their awful form Celtic could still extend their run of consecutive trophies to 12 if they win the Scottish Cup Final against Hearts on December 20.
Insisting he deserves a chance to keep going and turn things around as fans chanted 'Lennon, Lennon, get to f***' outside, the Northern Irishman there might now be nothing he can do to recover the confidence of fans.
'What can I say? That's their opinion and it's been rumbling for a while. It doesn't matter what I say or what bravado I put on because it won't wash. I have to turn it round with results.