Bertrand Traore put Vitesse ahead at the GelreDome, before Kolbeinn Sigthorsson pulled the league leaders level just after the break.
The result saw Ajax remain on the verge of claiming a fourth successive Dutch title, but the fixture was marred by crowd violence, with approximately 60 fans of the Amsterdam outfit ejected from the ground.
And Vitesse revealed on Monday that they were working with the police to identify those involved in the disturbances, which occurred during the first half.
"Vitesse regrets the situation that has arisen during the match and will put everything in its power to (identifying) the parties, together with the police," read a statement on the club's website.
"Both clubs see the current situation as an incident.
"Vitesse want to emphasize the positive support of its own supporters. The vast majority of the Vitesse audience are not to blame."
