Violence following Sunday’s Old Firm clash between Rangers FC and Celtic FC at Ibrox Stadium has been described as “completely and utterly unacceptable” by Scotland’s First Minister John Swinney.

The teams met in the Scottish Cup quarter-final, with Celtic winning after a tense penalty shootout.

Disorder broke out after the final whistle when supporters invaded the pitch. Police described the scenes as “shameful”, and officers made a number of arrests.

Speaking to the Press Association on Monday, Mr Swinney condemned the violence.

“The violence after the Old Firm game yesterday at Ibrox was completely and utterly unacceptable. There is no justification for it whatsoever,” he said.

He warned the incidents created serious risks for everyone inside the stadium.

“Fans, police officers and stewards faced severe danger. The behaviour was unacceptable in every respect.”

The First Minister also said Police Scotland has his full support as it investigates those responsible.

“I want to make clear that the police have my full backing to pursue and arrest everyone involved,” he said.

He added the Scottish Government will work with both clubs and the Scottish Football Association to prevent similar incidents.

“The clubs must be horrified by what they witnessed,” he said. “We will work constructively with them and with the SFA to make sure these incidents have no place in Scottish football.”

Supporters also used pyrotechnics during the pitch invasion. Mr Swinney said such behaviour increases the danger inside stadiums.

“Pyrotechnics exaggerate and escalate the level of danger,” he said. “We must work with authorities to ensure they are not brought into football grounds.”

His comments came after the head of a supporters’ organisation criticised the scenes.

Speaking on BBC Radio Scotland, Stuart Murphy, chief executive of the Scottish Football Fans Association, described the situation as a “debacle”.

“I’m angry this morning,” he said.

“I’m angry on behalf of the majority of decent fans who will feel tarnished by what happened yesterday. ‘Debacle’ is the only way to describe it.”

Murphy said the violence shows the game has not moved forward since a notorious clash between supporters more than four decades ago.

“I attended the Old Firm cup final 45 years ago. Sadly, it feels like we have not moved on since then.”

After the 1980 Scottish Cup Final at Hampden Park, supporters from both sides fought on the pitch and police arrested more than 200 people.

The incident led to a nationwide ban on alcohol sales at football matches in Scotland, a rule that still applies today.

Former Scottish Football Association chief executive Gordon Smith said authorities may need to consider banning away supporters from Old Firm matches.

“If I was still in charge, I would seriously consider removing away fans from these fixtures,” he told BBC Radio Scotland.

He argued that mixing rival supporters often leads to trouble.

“If there had been no away fans at the game yesterday, we likely would not have seen anything like those scenes.”

Following the match, Kate Stephen condemned the behaviour.

“The conduct of a number of supporters at the Scottish Cup quarter-final between Rangers and Celtic was shameful,” she said.

She confirmed officers have already made several arrests.

Police will now work with both clubs and the Scottish Football Association as part of a full investigation.

Stephen said officers and stewards faced sustained hostility during the incident.

“Some individuals armed themselves with items clearly intended to cause harm,” she said.

Several officers and members of the public suffered injuries during the disorder.

Police are also investigating reports that some supporters entered the Broomloan Road stand without tickets before the match began.