Mayor of London Sadiq Khan has condemned the ugly scenes which marred West Ham's 3-0 home defeat to Burnley at the London Stadium on Saturday as "disgraceful", his spokesperson said.
The Hammers are facing an investigation by the Football Association after a series of pitch invasions and widespread supporter unrest, which saw the club's co-owner David Sullivan struck by a coin towards the end of the game.
On Monday morning, a spokesperson for the Mayor of London said: "The disturbances at the London Stadium were disgraceful and it's clear that there cannot be a repeat of the ugly scenes witnessed on Saturday.
"It is up to West Ham to carry out a thorough investigation, together with stakeholders, and take proper action against those supporters who misbehaved."
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Stewarding is overseen externally via the stadium operators E20, and has been a frequent problem for the Hammers since their move from Upton Park.
The latest incidents at the converted Olympic Stadium have raised fears that the club could be punished by having to play a future game behind closed doors.
West Ham were not available for immediate comment when contacted by the Press Association on Monday.
In December 2017, the mayor announced he would take over full control of the stadium, with the London borough of Newham withdrawing from the partnership which owns it following the publication of an independent review. That review said there had been "a catalogue of errors" resulting in massively increased costs over conversion after the London 2012 Olympics.
The spokesperson for the mayor made reference to the latest concerns over safety issues in Monday's statement.
"Stewarding and the safety of supporters remain the responsibility of both the club and the stadium operators, LS185. This is clearly laid out in the terms of the contract negotiated by the club under the previous mayor," the spokesperson added.
"Following the publication of the Moore Stephens report, Sadiq has publicly expressed his commitment to meeting with Baroness Brady (West Ham vice-chairman Karren Brady) to discuss the future of the stadium and its financial situation and hopes to set up a meeting in this regard in due course."
West Ham are next scheduled to play a home Premier League match against fellow relegation battlers Southampton on March 31.
Following the events of Saturday, the club swiftly issued a statement saying they were "committed to taking decisive and appropriate action", with an emergency meeting called of all London Stadium stakeholders.
The London Legacy Development Corporation, meanwhile, confirmed there is to be an "urgent and forensic review" into how events unfolded at the stadium on the Queen Elizabeth Olympic Park.
"Security arrangements for Saturday's game were in line with the requirements of the licensing authority and informed by Police advice. The vast majority of people attended and went home safely without incident," a statement from the LLDC read on Monday.
"We will be working closely with the operator who will be conducting an urgent and forensic review."