Spectators at a university sports day were injured after a rugby match descended into violence.
Police were called as disruptive fans spilled on to the pitch during a varsity match between the universities of Brighton and Sussex.
Rival groups reportedly became embroiled in a mass fight, with bottles being thrown, banners of opposing fans burnt and flares let off.
One student was even said to have threatened another with a knife, The Times said.
Police said a person had been arrested on suspicion of carrying a weapon, but later released.
People were also abused with misogynistic, homophobic and racist language, Sussex students’ union said.
A small number of spectators were injured and received first aid on site, while some were taken to hospital as a precaution.
The two universities have condemned the behaviour as “shocking and disgraceful”, promising students involved would face “serious consequences”.
In a joint statement, Adam Tickell, vice-chancellor of the University of Sussex, and Debra Humphris, vice-chancellor of the University of Brighton, said: “The scenes witnessed at the annual Varsity sports day were shocking and disgraceful.
“A full investigation has been launched into events and any students identified as having participated in the disorder will face serious consequences under our codes of discipline. We unreservedly condemn the behaviour.
“The future of fixtures will be under review as part of our wider investigation.”
The brawl erupted on Sunday as the two universities competed in sports including football, hockey and cricket.
The rugby match had to be abandoned as stewards fought to contain the violence.
Sussex students’ union said the “violent and intimidating” behaviour had come despite it bringing in outside security for the first time.
It said: ” The dangerous and disrespectful conduct of a small number of spectators endangered other spectators, staff and players and resulted in the men’s rugby fixture being curtailed following discussions with the referee.
“This level of disruption and violence was unprecedented at previous varsity fixtures, with bottles thrown at the crowds and security staff as well as other dangerous behaviour.
“The behaviour included misogynistic, homophobic and racist language. We, along with the vice-chancellors of Sussex and Brighton, condemn these actions.
“It is a shame that this misconduct marred the great behaviour and sporting conduct of the majority of the spectators and all of the players on both sides.”