These are the pictures which show an altercation on the City Ground pitch, following Nottingham Forest's win over Derby County.
There was an incident after Sabri Lamouchi's Reds beat the Rams 3-0 on home soil in the second round of the Carabao Cup on Tuesday night, thanks to goals from Albert Adomah, Joe Lolley and Joao Carvalho.
It happened while Derby's substitutes were warming down after the final whistle and members of the Forest ground staff were tending to the playing surface.
The two managers, Lamouchi and Phillip Cocu, were both giving post-match interviews to the media at pitchside at the time.
It is understood by Derbyshire Live the two clubs are in dialogue as they look to establish exactly what happened.
