WATCH - Seven arrested as violence between rival fans mars West Ham's EFL Cup win over Chelsea
Police made seven arrests after violence marred West Ham's EFL Cup London derby win over Chelsea at the former Olympic Stadium on Wednesday night.
Skirmishes broke out towards the end of the Hammers' impressive 2-1 fourth-round win as police and stewards battled to maintain segregation behind the goal being defended by West Ham.
Coins, seats and other objects appeared to be thrown between rival supporters, with the Hammers and Chelsea condemning the unsavoury scenes which the authorities are certain to scrutinise.
The Metropolitan Police later announced seven arrests had been made.
Ugly scenes at the London Stadium as West Ham and Chelsea fans clash. Seats being ripped out and thrown pic.twitter.com/jUcQfzemTr— BigSport (@BigSportGB) October 26, 2016
Antisocial behaviour legislation was utilised prior to the match to order 30 people to disperse, the Met said.
Commander BJ Harrington, who was leading the police operation, said: "We have already made seven arrests and will work tirelessly to identify people involved and bring them to justice."
The Hammers vowed to ban any fan implicated in the disorder, while Chelsea have a history of taking the sternest available action in incidents of violence.
A West Ham statement issued following the match read: "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.
"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."
A Chelsea spokesman said on Wednesday night: "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 manager Slaven Bilic described the scenes as "unacceptable" and Chelsea head coach Antonio Conte expressed his disappointment.
The Hammers have been occupants of the London Stadium for just nine competitive games after leaving Upton Park in May - and 23 fans have already been banned this season.
There had already been disturbances in the stands and outside the ground at some of West Ham's previous home matches, and a series of measures were put in place ahead of a first London derby.
The capacity is capped at 57,000 and 45,957 were in attendance, along with a heavy police presence. Chelsea sold out their allocation of 5,182 tickets.
The clubs appealed to supporters for the tie to pass peacefully, but the entertaining match was overshadowed.
West Ham were 2-0 up before the worst of the violence took place. Cheikhou Kouyate rose ahead of restored Chelsea captain John Terry to head the Hammers in front and Edimilson Fernandes struck a second three minutes after the interval.
The energetic and pacey Hammers exploited uncertainty in Chelsea's defence, with Terry making his first appearance in more than six weeks following an ankle injury.
Chelsea had won three games in succession, scoring nine times without conceding, before West Ham brought the run to an abrupt halt.
Bilic was unhappy to have to address the violent scenes in his post-match media conference, having already described the evening as "a great night for us".
West Ham play at Manchester United in the quarter-finals.
Bilic said: "It was a great game of football, not only for us. It was a cup game, night game, packed stadium, London derby, against a team that hit great form recently, totally on fire.
"To put that kind of performance from us is really very important for us, not only for this competition but in general to gain more confidence in the team."
Conte, who made seven changes to the starting XI which began Sunday's 4-0 win over Manchester United, said: "When you lose, it's normal you see bad things. In this game I found a lot of positive things."