According to the Westdeutsche Allgemeine Zeitung (WAZ), Ruhr Valley referees have become so upset about violence that they'll no longer officiate games involving five amateur teams, citing players and fans' behaviour.
That includes threats and attempted attacks on game officials, Volkan Alan, the head of the local association of referees, told the WAZ.
In one recent incident, a spectator physically attacked a referee, forcing the police to be called. On another occasion, an assistant referee was pelted with a cup of beer.
One player even threatened to “cut open” an up-and-coming 18-year-old referee, Alan said.
“What should a young person think after such a threat?” Alan asked the WAZ.
Violence at sporting events isn't limited to the Ruhr region, but is a growing national problem.
In September, unions representing police reported that lower level football matches across the country were becoming more dangerous because security has been neglected.
Organisations representing referees have reported similar issues. In Berlin earlier this year, a referee was punched and had to be temporarily hospitalised after showing a red card to a player.
Last weekend the Berlin Football Association paused all games for five minutes in a coordinated effort, in order to raise awareness about violence against referees.
But three games had to be cancelled anyway on Sunday due to attacks on referees.
“They underline the importance of and how correct our action was,” association head Bernd Schultz told the Berliner Morgenpost. “The number of verbal and physical attacks on match officials is increasing. This is a general social problem.”
It's not clear how to stop the attacks other than lay down harsh penalties such as suspensions and fines against violent players.
One option not yet used in Germany: Punishing the entire team by relegating them to a lower division, something that's being tried out in the Netherlands.
In any event, something has to be done, Alan said. Even youth games are becoming dangerous for referees, he told the WAZ.
“Even there, the referees are spat upon and harassed,” he said.