Police Scotland has criticised the “lack of support from Rangers Football Club” over failing to order thousands of fans who gathered in Glasgow on Sunday to go home.
Fans congregated in George Square and outside Ibrox Stadium after Rangers took their first top-flight title in 10 years.
Police made 28 arrests and seven people were issued with fixed penalty notices or will be reported to the Procurator Fiscal.
Reasons for arrest included assaulting police officers, breaching coronavirus regulations, disorder, use of flares and sectarian breaches of the peace.
Deputy Chief Constable Malcolm Graham said: “The behaviour which we saw at the weekend was disgraceful and I utterly condemn the individuals who chose to completely disregard the coronavirus regulations, putting both the wider community and our officers at risk.
“I also strongly condemn the lack of support from Rangers Football Club over the messages we repeatedly asked them to put out to persuade fans not to go out celebrating and encourage those who did gather in large numbers to return home.
“We’ve been planning for the conclusion of the football season for some time since the league was allowed to resume and the sport is in a very privileged position given the restrictions seen across the country for almost a year.
“It was very clear through the lack of messaging that Rangers did not take seriously their responsibilities in terms of seeking to persuade their fans to celebrate safely and responsibly.”
He added: “I commend the officers who delivered a policing operation which was entirely consistent with our approach throughout this pandemic to maintain public safety and minimise disorder, disruption and damage to property.
“They did this faced with considerable danger, all of which was completely unnecessary and avoidable.
“Where large numbers of people gather at an unplanned event such as this, we use established crowd control measures to ensure we are keeping the public safe and manage those who are refusing to disperse.
“We will work with football clubs, local authorities and the Scottish Government to ensure we do everything we can to persuade people that none of these scenes can be repeated as the football season continues.”
It comes hours after Deputy First Minister John Swinney said the “silence from Rangers was deafening” when speaking about the issue at the Scottish Government’s coronavirus briefing on Monday.
Mr Swinney congratulated the club on their win and praised those who celebrated at home, but said the behaviour of some fans was an “absolute disgrace”.
He said: “To see so many people deliberately flouting (coronavirus) rules with no regard for the safety of others is shameful.
“Events like yesterday risk spreading the virus and they show no regard or respect at all for the millions of households across Scotland who have been sticking to the rules, who haven’t been able to meet up with friends and families to fully celebrate birthdays and other milestones or, in some cases, to attend funeral services of their loved ones.
“The Government and Police Scotland reminded Rangers of the need for the club to advise fans to adhere to the current restrictions in discussions on February 26 and March 5.
“It is a matter of profound regret that that did not happen.
“The Scottish Government will be making our extreme disappointment at the lack of leadership clear to the team management.”
He said Rangers had a “duty” to tell fans not to gather and messages from them on Sunday could have helped disperse the crowds.
Chief medical officer Gregor Smith told the briefing there is a “real risk” of a rise in Covid-19 infections following the gatherings.
Mr Swinney warned this could mean “difficult decisions” regarding lockdown easing.
In a statement, Rangers said: “During the last number of weeks, Rangers can confirm that we initiated open dialogue with key stakeholders in relation to the possibility of us achieving a historic 55th league title.
“We have proactively engaged with our local MP, the Justice Minister, the Scottish Government, Police Scotland and the SPFL in relation to maintaining a cohesive message regarding public safety during the Covid-19 pandemic.”
The club said they understand the “jubilance” of their fans and highlighted “frustration” over the closure of stadiums.
The statement continued: “We reiterate the message from our manager, Steven Gerrard, who highlighted that fans should adhere to government guidelines: stay safe, socially distance and look after each other in this difficult time.”
The club said they will continue talks ahead of future milestones to “maintain a cohesive message in relation to government guidance”.
Police Scotland Chief Superintendent Mark Sutherland, divisional commander for Greater Glasgow, previously said there were a number of minor injuries to members of the public, some through intoxication.
He added the police operation was pre-planned and praised officers, saying many “put their own health at risk”.
Some politicians had criticised the police response, with Scottish Green MSP Ross Greer tweeting: “Expect Police Scotland to explain pretty quickly to Parliament why they decided to facilitate rather than disperse multiple mass gatherings during a national lockdown today.”
First Minister Nicola Sturgeon said on Sunday the “infuriating and disgraceful” scenes could jeopardise plans to ease the coronavirus restrictions and urged Rangers to ask people to go home.
On Monday, Scottish Labour leader Anas Sarwar warned fans of the dangers they posed to themselves and their families by not adhering to the lockdown restrictions.
David Hamilton, chairman of the Scottish Police Federation which represents rank and file officers, told BBC Good Morning Scotland he was “appalled” by the scenes and said almost all of the officers on duty will not yet have been vaccinated and he is concerned for them.