West Ham have launched an investigation following fresh reports of crowd trouble at the London Stadium on Saturday and vowed to take a "zero tolerance policy" against any "mindless individuals" found guilty.
Several arrests were made as clashes broke out between rival supporters outside the stadium in the wake of the Hammers' 1-1 draw against Middlesbrough.
The violent scenes marked the third time this season there have been disturbances at the ground.
West Ham's first Premier League home game at the venue, a match against Bournemouth, was marred by scuffles both inside and outside the ground, while last month's clash with Watford saw 10 people ejected from the stadium.
And the club has vowed to crack down on those involved in such incidents.
"West Ham United will investigate incidents involving both sets of supporters outside London Stadium after [Saturday's] 1-1 draw with Middlesbrough," said a club spokesperson via a statement.
"Metropolitan Police have confirmed that two men were arrested on suspicion of affray and the third was arrested on suspicion of assaulting a police officer. All three currently remain in custody pending further enquires.
"This behaviour has no place in football and West Ham United, with cooperation from all London Stadium stakeholders, including the police, Stadium Landlords E20 and Stadium Operators LS185, will continue to operate a zero tolerance policy on such incidents.
"We must stress that the vast majority of the more than 400,000 supporters who have attended a game at the stadium since August have behaved impeccably and we will not let the acts of mindless individuals tarnish their reputation."