Seven people have been arrested following the violence which erupted inside the London Stadium during West Ham's EFL cup tie with Chelsea. Met Police said they will "work tirelessly" to identify all those who were involved in the clashes between both sets of fans which began while the match was still being played.
Riot police were forced to intervene as fighting broke out in the Sir Trevor Brooking stand, with missiles including chairs and coins also been thrown between the supporters of the London-based clubs.
Prior to the game, fans were warned they would be subjected to increased security measures, subject to body searches, alcohol restrictions and post-match segregation as the West Hams new stadium has been marred with crowd trouble ever since the move to Stratford for the start of the season.
Following the latest violence, seven men were arrested for public order offences and are currently in custody at various police stations.
An additional 30 people were issued with directions to disperse under antisocial behaviour legislation prior to the match.
West Ham eventually won the game 2-1 thanks to goals from Cheikhou Kouyate and Michy Batshuayi.
Commander BJ Harrington, who was leading the police operation, said: "Although the vast majority of people left the stadium peacefully and were well behaved, there were a minority of people who attended the match that were clearly intent on being involved in confrontation and violence.
"Despite extensive work with both clubs and the London Stadium partners as well as a large and robust policing operation, there were unacceptable incidents inside and outside the stadium, before, during and after the game.
"We welcome the condemnation from partners and have already started a post match investigation. We have already made seven arrests and will work tirelessly to identify people involved and bring them to justice."
A spokesperson for West Ham United said: "West Ham United and London Stadium partners unreservedly condemn the behaviour of individuals involved in incidents during this evening's fixture with Chelsea.
"Whilst quickly brought under control, the Club, in line with its clear zero tolerance policy, will work closely with London Stadium 185, the Metropolitan Police Service and Chelsea to identify the individuals involved.
"London Stadium is fitted with a state of the art Panomera CCTV system which provides HD footage of every area of the ground and has led to the successful identification and subsequent banning of 23 individuals already this season.
"Once identified, those found to have acted improperly will be banned from attending any West Ham United fixtures for life and we will request the courts serve banning orders to prevent these individuals attending any other football.
"West Ham United have 10,000 under-16 season ticket holders and 25,000 supporters who attend as part of a family unit, and the Club and Stadium partners have been working hard to ensure that the Stadium is a safe and family friendly environment for all home and away supporters.
"As such, the purchase of tickets for tonight's fixture was limited to supporters with a recorded West Ham United purchase history and limited to only one ticket per person. We must stress that the overwhelming majority of supporters who have visited London Stadium have supported the team exceptionally and behaved impeccably."
A Chelsea spokesperson added: "The club is extremely disappointed to see disturbances at the end of tonight's game and we condemn such behaviour."