Police have warned about the dangers of setting off flares and pyrotechnics inside football stadia as they continue to investigate last Saturday's off-field incidents at Stamford Bridge.
The Met's Central Football Unit and the Football Association are still reviewing footage aft er several flares, 'smoke bombs' and 'thunderflash' pyrotechnics were set off during Chelsea's 2-1 loss to Crystal Palace.
Five people were arrested on Saturday, including two for possession of a flare. Officers also recovered a number of flares and pyrotechnic devices that were found hidden inside toilets at the stadium and a rucksack full of pyrotechnics that was found in nearby Brompton Cemetery.
Inspector Matt Ashmead said in a statement: "Several devices were let off inside the away end at Stamford Bridge on Saturday and officers seized a number of other devices on the day as well.
"Flares and pyrotechnic devices inside stadia are very dangerous and they can reach extremely high temperatures. There is a very good reason that they are banned from football matches, as they can cause horrific injuries and can also be frightening for the many young fans that attend matches.
"Some fans might think that setting off a flare is a good way to support your team, but it is putting yourself and fellow fans at risk. Bringing flares to football matches is completely unacceptable and you can expect to be arrested and charged if you are caught in possession of such a device."
Four loud bangs were heard coming from the area of the Shed End which housed visiting Palace fans, with smoke bombs and at least one flare visible.
Two people were arrested in the visiting end for allegedly setting off the first pyrotechnic, which followed Wilfried Zaha's equaliser, the Metropolitan Police told Press Association Sport at the weekend.
A third person was arrested for allegedly assaulting a steward who was attempting to deal with the incident.
There were five arrests in total around the match, with two relating to possession of Class A drugs, the Met said.
Two loud bangs followed Zaha's ninth-minute equaliser after Cesc Fabregas had put the Blues in front.
And a third followed when Christian Benteke struck in the 11th minute with a goal which proved to be the winner.
There was a fourth, with a red flare visible soon afterwards, just prior to the final whistle being blown.
:: Anyone with information can contact the Central Football Unit via 101, or by tweeting @MetCC; To give information anonymously call Crimestoppers on 0800 555 111 or visit crimestoppers-uk.org.