Liverpool are working to identify and ban the pitch invader who collided with their players during goal celebrations in Sunday's 7-0 win over Manchester United.

Jurgen Klopp's side claimed a record victory against their rivals as Cody Gakpo, Darwin Nunez and Mohamed Salah each scored braces on a stunning day at Anfield.

During the celebrations for Roberto Firmino's seventh goal of the game, however, a supporter ran onto the pitch to join the players, slipped and collided with Andy Robertson.

Liverpool left-back Robertson was knocked to the ground, and the incident prompted a furious reaction from Klopp, who could be seen shouting at the culprit as he was removed by security.

Further action is to come, the club confirmed in a statement on Monday.

"Liverpool FC has begun an immediate investigation to identify and ban the individual pitch runner from Sunday's Premier League fixture against Manchester United at Anfield," it read.

"The offender ran onto the pitch and collided with Liverpool players, risking injury, as they celebrated the seventh goal in front of the Main Stand.

"There is no excuse for this unacceptable and dangerous behaviour. The safety and security of players, colleagues and supporters is paramount.

"The club will now follow its formal sanctions process and has suspended the alleged offender’s account until the process is complete.

"If found guilty of the offence of entering the pitch without permission, the offender could face a criminal record and a lifetime ban from Anfield and all Premier League stadiums.

"These acts are dangerous, illegal and have severe consequences."