Kick-off in the Europa League group stage match between Arsenal and Cologne was delayed by an hour in the interests of crowd safety.
The group H clash was due to kick-off at 20:05 BST. However, Arsenal's official Twitter account announced that kick-off had been delayed just 45 minutes before the match.
"The kick-off of #AFCvCOL has been delayed by an hour in the interests of crowd safety," the club said.
Earlier in the day, British media reported that 20,000 Cologne fans had made their way through London on their way to the Emirates, although only 3,000 tickets were allocated for the German club.
Media reports suggested that the volume of fans around the stadium was preventing home supporters getting in, and therefore had necessitated the delay.
The kick-off of #AFCvCOL has been delayed by an hour in the interests of crowd safety
— Arsenal FC (@Arsenal) September 14, 2017
Hundreds of Cologne supporters were being held behind a police cordon as order was being restored in and around the away turnstiles.
Fans took to the streets in their numbers, with social media posts showing hordes of supporters singing and marching around Oxford Circus hours before the scheduled kick-off.
Ahead of the delay, Arsenal's official website warned Cologne fans they faced being asked to leave the stadium if they purchased tickets in the home sections of the ground.
"Please note visiting supporters that purchase a ticket in the home end for this fixture are likely to be ejected from the stadium," a statement on their website read.
Cologne currently sit bottom of the Bundesliga having lost all three of their league games so far - but they reached the Europa League having finished fifth last season.
Head coach Peter Stoger was asked on the eve of the game if he had a message for the thousands of fans making the trip, to which the Austrian replied: "Enjoy the pubs!"
No further delays were anticipated but another problem occurring was the number of away fans attempting to enter the home sections of the stadium with legitimate tickets.
