Police have made eight arrests as they investigate "disorder" during and after Sunderland's game against Coventry City yesterday.
Officers have confirmed they are investigating trouble which flared at the Stadium of Light.
Reports were made of objects being thrown from the away end into the stands below.
A number of Sunderland fans have said they saw items including bottles, coins and even flares being thrown into the lower area of the North Stand of the stadium from the upper section of the stand which housed away supporters.
A spokesperson for Sunderland AFC said that several fans were injured after being hit by items or had property damaged at the game.
Video footage has also emerged on social media which it is claimed shows Sunderland and Coventry City fans fighting in a pub.
Police made eight arrests in total yesterday resulting in one man being charged with breaching a football banning order, two men being charged with public order offences and three men being released under common law.
Two men faced no further action.
Five further people were ejected for breach of ground regulations.
Northumbria Police has confirmed it is working with Sunderland AFC and Coventry City FC as they investigate the matter.
Match commander, Chief Inspector Jamie Pitt, said: "While the majority of fans who attended the match behaved incredibly well, the actions of a small minority have spoilt the day for many and this is totally unacceptable.
"Notwithstanding there was a notable steward and police presence at the ground for the match we are aware of the issue of objects being thrown from the away end.
"There is absolutely no place in football for this sort of behaviour and we are working closely with both clubs to help locate those responsible and we will take action on anyone found to be involved."
A spokesperson from Sunderland AFC said: "Sunderland AFC is disappointed by the disrespectful behaviour of many away fans at the home match against Coventry City yesterday.
"SAFC and Northumbria Police had been in contact with both Coventry and its fans group ahead of the game, acknowledging that there would likely be some sort of protest, and trying to ensure that the match could go ahead in a safe and respectful environment for both sets of fans.
"That turned out not to be the case, with Sunderland fans in the lower tier of the North Stand being subjected to projectiles thrown from the upper tier, where away fans were housed.
"Several Sunderland fans were either injured by the projectiles or had property damaged by smoke bombs thrown from above.
"There were numerous other offences committed, all of which were especially disappointing given Sunderland AFC 's willingness to speak to Coventry fans ahead of the game.
"In response, Sunderland fans demonstrated admirable restraint in the circumstances, for which the club is grateful."
Anyone with any information about the incident is asked to contact police on 101 quoting reference 382 13/04/19.