|More than 20.000 FC Cologne fans descended on The Emirates, the large majority without tickets|
Fellow Serie A sides Atalanta and Lazio also won while Portugal’s Vitoria Guimaraes began their match against Salzburg with not a single European player in the team.
Arsenal’s Group H match was delayed by an hour as about 20,000 Cologne supporters fans descended on The Emirates, most without tickets, before kick off as their team returned to European competition for the first time in 25 years.
The reports added that the number of away fans around the stadium was preventing home supporters getting in, although the Arsenal fans were eventually able to enter the stadium.
The Metropolitan Police said extra officers had been sent to the stadium after scuffles broke out before kick-off.
A police statement said: “Officers are dealing with disorder at the Emirates Stadium where fans have gathered for the Arsenal vs FC Koln match. A policing plan is in place for the game. Additional officers have been deployed.”
The police later said four people had been arrested “on suspicion of public order offences”.
Asked if the number of Cologne fans at the match was a surprise, Arsenal manager Arsene Wenger told reporters: “They were very clever. I don’t know how they managed to infiltrate our fans and get everywhere but they did that very well.”
“Were the problems created by people who had no tickets? I don’t know. But certainly they (Cologne) had more people here than tickets so that was certainly the cause,” he said at the post-match news conference.
“I’ve followed German football for a long time and I thought Cologne had not played in Europe for 25 years. On the first night they go out (to play), they spoil their night. I couldn’t understand that.”
There were also scuffles between fans and when the action finally started, Arsenal fell behind to a stunning long-range strike from Jhon Cordoba before second-half goals from Sead Kolasinac, Alexis Sanchez and Hector Bellerin rescued the win.