Manchester United players had a coin thrown at them by an Arsenal supporter during their FA Cup victory at the Emirates Stadium on Friday night.
Towards the end of the game, with United leading 3-1, there was a contretemps between Arsenal defender Sead Kolasinac and United forward Marcus Rashford.
Players from both sides, including United star Jesse Lingard, stepped in, and the 26-year-old was involved in a verbal exchange with Arsenal supporters.
Lingard, who was confronted by Arsenal midfielders Granit Xhaka and Matteo Guendouzi, had to be pulled away by his United team-mates.
Kolasinac and Rashford both received yellow cards following their clash.
Television replays showed Ashley Young, who captained United, picking up a coin that had been thrown from the crowd and giving it to the assistant referee.
In the previous cup game played at Emirates Stadium, a Carabao Cup clash last month, Tottenham's Dele Alli was hit by a plastic bottle thrown by an Arsenal fan.
Lingard was amongst the scorers for United, with Alexis Sanchez and Anthony Martial also on target, while Pierre-Emerick Aubameyang netted for Arsenal.