Arsenal said they will investigate "two disturbing incidents" involving supporters during their 2-0 win over local rivals Tottenham on Sunday.
Mikel Arteta's side opened up an eight-point lead at the top of the Premier League table thanks to an own goal from Hugo Lloris and a long-range Martin Odegaard strike.
However, the club condemned antisemitic behaviour from some fans during the derby win and said anyone identified would receive a lengthy club ban, and their details would be passed to the police.
"We have been made aware of two disturbing incidents over the weekend involving antisemitism which are now under investigation," Arsenal said in a statement on Wednesday.
"There was an incident at the North London derby on Sunday involving Arsenal supporters in which one of our fans overheard grossly offensive antisemitic statements made by another Arsenal fan.
"On the same afternoon, we were appalled to hear of an incident at The Cally pub in Islington, involving other antisemitic chants.
"We recognise the impact this behaviour has on our many Jewish supporters and others and condemn the use of language of this nature, which has no place in our game or society.
"Arsenal must be a safe and welcoming environment for everyone, and we want to be clear that any kind of discriminatory abuse is not welcome at our club. We will not stand for this kind of behaviour and will take strong action against any supporters who we establish are responsible for such acts.
"Anyone identified will receive a lengthy club ban and their details will be passed to the police to commence legal proceedings."
The game was also marred after Arsenal goalkeeper Aaron Ramsdale was attacked by a Tottenham supporter at the end of the game.
Police confirmed on Tuesday that 35-year-old Joseph Watts has been charged with assault and is due to appear at Highbury Magistrates' Court on Feb. 17.