Manchester United's game against Liverpool was called off on Sunday after fans invaded the pitch in protest against the club owners' move to take it into the proposed European Super League.
Around 100 fans managed to access the pitch while thousands gathered outside the club grounds to demand that the American Glazer family sell the English football club.
The fans inside Old Trafford were seen waving from windows and were later involved in scuffles with police as they were ejected from the stadium.
Following discussions with police, Manchester United announced on Sunday evening that the game would be postponed.
"Our fans are passionate about Manchester United, and we completely acknowledge the right to free expression and peaceful protest," a club statement said.
"However, we regret the disruption to the team and actions which put other fans, staff, and the police in danger. We thank the police for their support and will assist them in any subsequent investigations."
Long-running anger against the American owners has boiled over after they were part of the failed attempt to take United into a European Super League.
“Get out of our club,” fans chanted as flares were set off. “We want Glazers out.”
The family has declined to engage with fans since buying United in 2005 in a leveraged takeover that loaded debt onto the club.
United and Liverpool players were unable to travel to the stadium.
If Liverpool had won the game, originally scheduled for 4.30 pm GMT, Manchester City - Manchester United's bitter rivals - would have clinched the English Premier League title.
Although Manchester United have been English champions a record 20 times, the club has not won the title since 2013, when long-time manager Alex Ferguson retired.