The KNVB dealt Ajax the unconditional sanction after the F-Side, the section in the Johan Cruyff ArenA, set off fireworks twice in the game against FC Groningen on November 30th, which was called off by referee Bas Nijhuis after the latest offence. The match was resumed on Tuesday, December 2nd.
The F-Side will be closed for the home game against Sparta Rotterdam on March 14th. Ajax have accepted the punishment without protest.
"This is an unconditional sanction for Ajax's home match against Sparta, without the responsible spectators (sections 025 to 029, 125 to 129 and sections 825 and 829)," the club said in a statement.
"The independent prosecutor for professional football took into account in the sentencing that Ajax had previously kept the relevant sections empty on its own initiative during the Klassieker match won on 14 December last year," Ajax said about the derby against Feyenoord last year, which was played without the F-Side after their offences against FC Groningen.
