Arsenal have confirmed that one of their fans was arrested for allegedly throwing objects at the Manchester United bench during Saturday's 2-1 defeat at the Emirates Stadium.
The incident happened shortly after Kieran Gibbs opened the scoring with a second-half own goal, and the club have now revealed that the supporter in question is facing a lifelong ban if found guilty of the offence.
An Arsenal spokesman said "A male was arrested at the stadium for throwing an object towards the Manchester United bench after the first Manchester United goal.
"There will be full co-operation between Arsenal and the Met Police - we do not tolerate anti-social behaviour. If found guilty, individual will also be banned by club."
The defeat signalled the Gunners' worst start to a season for 32 years.