LONDON (AFP) - An investigation has been opened into crowd trouble at Chelsea's League Cup match with West Ham at Stamford Bridge.
Police in riot gear were confronted by a section of the West Ham supporters after the match which Chelsea won 1-0.
Mateja Kezman, the scorer of Chelsea's goal, needed treatment on a head injury during the match after being hit by a missile, believed to be a coin.
The FA will seek reports from the clubs and the police, and will review video evidence and the referee's report.
Scotland Yard said there had been 11 arrests for alleged public order, drugs and offensive weapon offences.
This latest outbreak of crowd trouble took place just 24 hours after arrests were made across London at Millwall's New Den ground during their 3-0 third round defeat against Liverpool.
The Football Association is already looking into that incident.
10/28/2004 - 10:55 GMT - AFP