The Dutch football association KNVB is investigating racist chanting at Sunday’s match between Ajax and ADO Den Haag.

A group of ADO supporters repeatedly made monkey noises when Ajax player Riechedly Bazoer had the ball, despite being ordered not to over the loudspeaker system.

‘Monkey noises are disgraceful. We have handed the video and reports to the disciplinary committee,’ the KNVB said in a statement. The match was not halted, even though referees are able to take this step.

Ajax coach Frank de Boer described the chanting as disgraceful and praised the way Bazoer ignored the crowd and got on with the game. ‘Nevertheless, we should not accept this,’ De Boer said. ‘Not on the the pitch and not in the Netherlands.’

Ajax won the match 1-0.

Fines

Racist chanting is a persistent problem within some groups of supporters. In November, a group of Utrecht fans directed racist chants at Twente’s Ghanese player Thomas Agyepong.

In 2014, European football body Uefa fined Rotterdam football club Feyenoord for racist behaviour by fans during a Champions League match against Besiktas of Turkey in July.