Arsenal's Europa League game against Cologne was delayed by an hour after chaos broke out at Emirates Stadium.
There emerged masses of ticketless away supporters who had only been given a ticket allocation of 2900. Despite this, it is understood that 20,000 Cologne supporters made the trip to London.
This incident took place outside of the ground while a few fights broke out between the stewards and these fans after the gates opened.
According to BBC Sport, police said that four people had been arrested on suspicion of public order offences.
Despite the prior madness, Arsenal went on to claim a 3-1 victory with no further disturbances during the match.
BBC Radio 5 live correspondent Richard Conway reported witnessing these disturbances. Watch:
Koln fans fighting with stewards inside Emirates stadium. Group arrived in home end and fought their way into away section. pic.twitter.com/7RC17WZyz2— Richard Conway (@richard_conway) September 14, 2017