West Ham have threatened life bans to fans found to be involved in violent incidents that took place during the club's 4-2 defeat by Watford at the London Stadium on Saturday.
The club will also undergo a full security review of their stewarding procedures after fighting broke out between their own fans during the club's 4-2 home defeat by Watford.
It is understood that minor scuffles broke out between West Ham and their rival Watford supporters in the corner of Trevor Brooking Stand on Saturday afternoon.
On Saturday night, a club statement read: 'West Ham United unreservedly condemn the behaviour of the individuals involved in incidents during today's fixture against Watford.