Four are already in police custody following a clash in the West Ham fans section at Old Trafford in their 1-0 loss to Manchester United.
A spokesperson for Greater Manchester Police said a 33-year-old man had been arrested on suspicion of assaulting an emergency worker.
Other three were arrested for serious offences to include; A 21-year-old man arrested on suspicion of drunk and disorderly behaviour, possession of cocaine, and common assault, with a 22-year-old man arrested on suspicion of throwing missiles and a 23-year-old man arrested on suspicion of a public order offence.
