Sunderland captain Granit Xhaka appeared to be in a rage in a heated confrontation with a group of West Ham fans behind the bench at the London Stadium on Saturday.
The Swiss midfielder, 33, was embroiled in a tense war of words with a group of supporters sat behind the away bench as the Hammers' 3-1 win over Sunderland entered its final exchanges.
Such was the distraction caused by the argument that the match was briefly halted by referee Thomas Bramall, who discussed it with West Ham boss Nuno Espirito Santo.
Xhaka, who was not part of the Sunderland team due to an ankle injury, even appeared to continue the row after the final whistle ended.
As the Black Cats bench walked down to the tunnel, cameras panned to the 33-year-old confronting yet another fan before he was ushered away by staff.
It is unclear what caused the wrangle, described as a 'dispute with the fans' on TNT Sports, but the midfielder appeared visibly irate.
Sunderland manager Regis Le Bris told Match of the Day after the game: 'I don't know really [what happened], it's always a shame when something like that happens, but I don't know.'
Bramall was said to have been alerted by the video assistant that the issue was playing out on the bench.
Widely circulated footage on social media shows the Sunderland players pointing to supporters as hundreds of Hammers fans stood up and began taunting Xhaka.
Stewards then flocked to the bench, where the altercation was playing out. It is unclear if any fans were removed from the ground.
Xhaka had started all of the Black Cats' Premier League games this season before Saturday's clash in east London.
He picked up the knock in his ankle during last week's victory over Crystal Palace but travelled with the squad to watch from the sidelines.