Roda JC director Huub Narinx has hit out at a section of the club's fans for their behaviour during Sunday's 5-2 defeat at home to FC Groningen.
Supporters attempted to storm the main stand and main entrance both during and after the Eredivisie encounter in Kerkrade, which ended with 15th-placed Roda suffering their eighth defeat in 16 games so far this season.
"What happened is extremely bad for the club," Narinx told De Limburger newspaper. "It is not even connected to the defeat.
"This has nothing to do with being a fan of your club. Everyone can state his or her opinion, and they may also express their anger, but that must be done within the boundaries of decency."
Narinx added he would try to identify those responsible for on Sunday's unrest.
"In normal circumstances I am a man of dialogue, but at the moment I have my doubts about how to continue," he said. "We want to know who is responsible for this."
• Meanwhile, FC Utrecht coach Willem van Hanegem has announced his intention to step down from the post at the end of the season.
The 64-year-old will be out of contract next June, but has decided not to extend his stay because of the recent off-field problems at the club.
Four members of Utrecht's coaching staff were shown the door at the end of October, and although Van Hanegem survived the cull, he admits the continued strained relations at the club prompted his decision.
"Since that (the sacking of his assistants) happened, I have had the feeling the club leaders maybe want to get rid of me too," he told AD Sportwereld.
"I cannot interpret the lack of contact we have in any other way.
"So I will spare the club's owner (Frans van Seumeren) a dilemma and I will go myself. That is my own decision."