The Football Association has launched an investigation into the crowd trouble that overshadowed West Ham United's EFL Cup victory over Chelsea on Wednesday.
In the latest of a series of incidents at the Olympic Stadium, supporters of both clubs clashed late in the match which saw the home side win 2-1 and progress into the quarter-finals of the competition.
Police and stewards intervened quickly as coins and bottles were thrown with seats also torn out and thrown at rival fans.
Seven arrests were made in the aftermath of Wednesday's match with both Chelsea and West Ham condemning the scenes, having already promised life-time bans for anyone involved.
The FA have now begun looking into the latest spate of violence to erupt at the venue the Hammers moved into just last summer. A short statement from English football's governing body read: "The FA is investigating crowd disturbances at last night's EFL Cup match between West Ham United and Chelsea. We are in dialogue with all relevant authorities."
A Chelsea spokesman said of last night scenes: "The club is extremely disappointed to see disturbances at the end of tonight's game and we condemn such behaviour.
"It would be inappropriate to comment further until tonight's incidents have been investigated properly."
West Ham boss Slaven Bilic also condemned the behaviour in his post-match interview. "Whatever happened, we are totally against it, as a club. For those kind of things to happen, especially in England, is unacceptable."
West Ham also released a statement Wednesday night where they condemned "unreservedly the behaviour of individuals involved."
They added: "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 all involved.
"London Stadium is fitted with a state of the art 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."