Manchester City have complained to Liverpool after a fan allegedly spat on their backroom staff during Sunday’s 2-2 Premier League draw, media reported.
Sky Sports said Liverpool had opened an investigation into the incident.
Both City and Liverpool did not immediately respond to Reuters’ request for comment.
City manager Pep Guardiola said he was not aware of the incident at the time, but was later informed by his staff.
“I don’t know what happened,” Guardiola told Sky Sports after the game. “I heard something from the crowd – nothing good for the staff. But I don’t know exactly what. I didn’t see the images.
“I’m pretty sure that if this happened, I’m sure Liverpool will take measures about this person. Liverpool are very much out of this behavior.
“Nothing will replace my admiration for this club. It was the same story two, three years ago when we came here and they destroyed our bus – it’s certain people, not just Liverpool.”
City twice came from behind to win a draw at Anfield with Phil Foden and Kevin De Bruyne. Guardiola’s team is third with 14 points, at the level of Manchester United, Everton and Brighton & Hove Albion. They will next host Burnley after the international break on 16 October.