Nottinghamshire Police arrested a man who ran onto the pitch during Nottingham Forest's 4-1 victory over Leicester City in the FA Cup on Sunday.
"Investigations are in the very early stages and our enquiries into the circumstances surrounding the incident are ongoing," chief inspector Neil Williams said.
The man confronted Nottingham Forest players who were celebrating Joe Worrall's goal in the 32nd minute.
B/R FootballA 'fan' ran onto the pitch and attacked Nottingham Forest players while they celebrated scoring a goal vs. Leicester City today. <a href="https://t.co/0wx9A5Icwg">pic.twitter.com/0wx9A5Icwg</a>
This article will be updated to provide more information on this story as it becomes available.