Chelsea have announced that any fans spotted with flares or smoke bombs could be arrested at Stamford Bridge.
The warning has come after recent incidents at the Etihad Stadium during the Manchester derby, where flares were thrown onto the pitch and Manchester United defender Rio Ferdinand was struck in the eye with an object thrown from the crowd.
A statement on the club's official website said: "Chelsea Football Club reminds our supporters that taking flares, smoke bombs or anything similar into a stadium breaches Ground Regulations and using such objects is likely to result in arrest.
"Their use is extremely dangerous and risks serious injury to fellow fans. Unfortunately there has been an increase in incidents involving flares and smoke bombs in recent weeks and as well as fans facing prosecution, the club is liable to be charged by the authorities should this behaviour continue."
The Champions League winners also revealed that dogs will be used to "detect fans carrying such objects" at this month's League Cup semi-final away leg at Swansea City.
