AZ Alkmaar have issued 43 stadium bans after West Ham United fans were attacked during their Europa Conference League semi-final defeat.
Several Hammers players confronted the group of fans that had targeted an area containing their friends and family, who were unharmed.
The Premier League side won the second leg in the Netherlands 1-0 to secure a 3-1 victory on aggregate.
In a statement, the Dutch club said more bans could follow in the future.
European football's governing body Uefa will review reports of the incidents before deciding on any action.