Leicester City have complained to the Football Association over “abuse and intimidation” suffered by their fans in the FA cup fixture against Millwall.
The champions say that they received various complaints from their fans and that they will not accept the safety of their players, supporters and staff being “compromised”.
Millwall fans ran onto the pitch following their shock FA cup victory over Leicester at The Den.
Police were deployed following the full time whistle to keep the home fans away from the travelling Leicester support.
However, Millwall are disappointed that Leicester did not raise the issue on the day of the game and are “surprised” at the allegations made against their fans.
The FA will speak with the Premier League champions about the issue.
Millwall have been drawn away against Tottenham in the quarter final of the FA cup.