An attack on a referee at an amateur football match has been described as the "worst assault on a match official on British soil".
Sunday's incident occurred during a cup game organised by the Turkish Community Football Federation in north London.
The Federation says it is "shocked and disgusted" and "strongly condemns" the incident, which was filmed.
Police told BBC Sport they are investigating an alleged assault on a man in his late 20s.
The referee suffered only minor injuries during the game at New River sports centre in White Hart Lane, which saw Dumlupinar Yeni Malatyaspor beat GS FC 2-1.
The Metropolitan Police said it was called to a report of an assault at 19:15 BST in White Hart Lane.
The suspects had left the scene prior to their arrival and no arrests have been made, but enquiries are continuing.
"It was reported that the victim was surrounded and assaulted by several suspects," the police said.
Footage of the incident was sent to charity Ref Support as part of its Referee Abuse Must Stop campaign.
It shows a man being tackled to the ground and kicked on the floor by a group of people on a football pitch.
"This is the worst assault on a match official we have seen on British soil," said Ref Support's chief executive Martin Cassidy.
"The subject needs to be taken seriously and the FA referees department needs to allow a pilot of body cams at grassroots level, to not only act as a deterrent to assaults and abuse but also as an evidence-collecting device."
The TCFF and the London Football Association are investigating the incident while the Football Association says it has started a disciplinary process.
"Both the London FA and the FA condemn any assault on a match official and have offered support to the referee," said the FA.
The TCFF said it is also meeting the team involved to "discuss our options with regard to any action we will take against the club and individuals involved."
The Referees' Association (RA), a support network for referees, said: "We are very concerned about abuse, assaults and poor practice, which has been highlighted by the recent incident in London. One assault is one too many."
Ian Braid, managing director of Duty of Care in Action Sport, added: "The trend of increasing abuse of match officials is something sport, not just football, needs to address, not only for the wellbeing and welfare of the individuals involved but to address the trend of declining numbers of people volunteering to be an official."