Two fans arrested for alleged racism
The two men have been bailed to return to later this month and the Metropolitan Police is also investigating incidents of coin-throwing at the game at Stamford Bridge.
Coins and other objects were thrown in the direction of Chelsea's players as they celebrated Frank Lampard's goal in the 2-0 victory over the Hammers.
The Football Association said it will liaise with the police and the two clubs involved.
Police later confirmed the two men arrested were from the section of West Ham fans at Stamford Bridge.