The two clubs played out a goalless draw in the match week eight fixture but the game’s major talking point centered on Pepe getting sent off by referee Anthony Taylor after head butting Alioski six minutes after the break.
Pepe has received widespread criticism for his conduct on the field of play while Alioski was not left off the hook either, with many believing that the Macedonian was guilty of playacting.
Criticism of the pair continued on social media but some of the reactions were overly excessive, and the two clubs have come out to condemn them.
"We utterly condemn the vile abuse directed at Nicolas Pepe and Ezgjan Alioski on social media following our match against Leeds United," Arsenal's statement read.
"This is completely unacceptable and we will be working with the police and authorities to do everything we can to trace and prosecute the culprits.
A Leeds statement, posted at the same time as Arsenal's, added: "The vile abuse directed at Ezgjan Alioski and Nicolas Pepe on social media after yesterday's Premier League game with Arsenal will not be tolerated by Leeds United.
"We will work closely with the police and the footballing authorities to ensure those responsible are identified and punished."