The Football Association are investigating an on-pitch incident during Arsenal's 3-2 win over Liverpool on Sunday.
Players from both sides were involved in a heated exchange during a frantic second half, with Michael Oliver informing managers Mikel Arteta and Jurgen Klopp of the incident both during and after the match.
The FA said in a statement: "We are aware of an incident that took place during the match between Arsenal and Liverpool. We are in dialogue with the match officials and will review the details of the incident."
During Sky Sports' coverage of the game, presenter David Jones said: "What we understand has happened is something has been said on the field.
"The referee, Michael Oliver, has come over to speak to the managers and what we're being told now is that that matter has been referred to the Football Association. And any further comments on it will come from them."
Klopp was asked about the incident post-match by reporters but revealed he was unable to shed any light as the matter had already been referred to the FA.
Arsenal ran out 3-2 winners at the Emirates Stadium following a first-minute strike from Gabriel Martinelli and a brace from Bukayo Saka. Liverpool had twice equalised through Darwin Nunez and Roberto Firmino.