The English FA are starting an investigation into the objects thrown at players during Chelsea's Worthington Cup semi-final against Tottenham.
Chelsea have begun their own inquiries after a bottle narrowly missed Les Ferdinand as he celebrated his equaliser in last night's game at Stamford Bridge.
They have also called on Tottenham to help find the supporters who threw coins at striker Jimmy Floyd Hasselbaink as he received treatment on the side of the pitch.
Both clubs would be likely to ban any supporter found to have stepped out of line, with Chelsea also promising further action after three fans were arrested for invading the pitch.
However, the FA will also examine whether there is anything further the clubs could have done to control their fans, with the possible sanction of heavy fines.
A Scotland Yard spokeswoman today confirmed there had been over 20 arrests in or, mostly, around Stamford Bridge last night due to football-related offences.
One man suffered minor stab wounds to the stomach outside the ground at 5.20 p.m., and another sustained head injuries. Chelsea supporters threw missiles at police from a pub on Fulham Road.