Former West Ham defender Tony Gale has described the club's London Stadium as "a powder keg" after trouble marred Wednesday's 2-1 EFL Cup win over Chelsea.
The Football Association has launched an investigation into the violence, with the Metropolitan Police having confirmed that seven arrests were made.
Stewards and police in riot gear were forced to come between supporters squaring up in the Sir Trevor Brooking Stand in the final minutes of the first London derby to be played at the former Olympic venue.
Plastic bottles, coins and several chairs were thrown in the clashes.