The group entered the A4 highway - one of the busiest in the country - near Hoofddorp to approach the team bus, which had left the Johan Cruyff ArenA shortly before, and lit flares. Another group of fans banged on the bus upon its departure, causing minor damage, a team spokesperson confirmed.
The Ajax fans caused a traffic jam on the A4, but the bus managed to avoid any incidents.
Rijkswaterstaat, the Directorate-General of the Ministry of Infrastructure and Water Management, issued a statement condemning the actions of the Ajax fans: "Rijkswaterstaat condemns this extremely dangerous behaviour. By doing so, they are not only putting their own safety at risk, but also that of other road users."
Away fans have been banned in the Klassieker between Ajax and Feyenoord since 2009.