Arsenal have said they will assess their safety procedures after a man ran onto the pitch at the Emirates during their 1-0 Europa League win over Qarabag.
Late into the second half a Qarabag supporter entered the field of play holding a political flag above his head in relation to the conflict between Armenia and Azerbaijan.
The fan tried to approach Armenia international Henrikh Mkhitaryan, who was on the bench, but the security got to him quickly.
Arsenal commented: "All of the safety procedures at Emirates Stadium are regularly reviewed, and in light of Thursday night's incident, we will be assessing whether we can make our pitch incursion procedures even more robust.
"It is extremely rare for anyone to get on the pitch at Emirates Stadium, as attempts are usually stopped by our many trained stewards on the track."
The supporter, who was also wearing a t-shirt with the portrait of former Armenian war commander Monte Melkonyan, was halted by someone from Arsenal's dedicated 'pitch runner squad' and immediately handed over to the police where he was arrested.
Alexandre Lacazette scored the only goal of the game in the 16th minute as Unai Emery's men topped Group E with 16 points, a win which means the Gunners extend their unbeaten run to 22 matches.