FC Cologne was fined 595,000 euros ($641,800) on Wednesday for igniting pyrotechnics and hurling objects on the pitch, which caused a match to be delayed.
The fine is the largest ever imposed for supporter misbehavior in German sport.
The German FA (DFB) penalized the club for the incident that delayed Cologne’s home derby against Borussia Moenchengladbach by several minutes in October.
The club can invest roughly one-third of the fine in security or other preventative measures.
Cologne has committed to seek for a “significant reduction” in the punishment, with managing director Christian Keller claiming the sentence will cause “enormous financial damage” to the club.
Keller admitted that “pyrotechnics are a part of football fan culture” while conceding “the red lines which must not be crossed… were clearly exceeded against Gladbach.”
Cologne won the match 3-1, their only league victory this season.
Despite being illegal, pyrotechnics are widespread in German football and are routinely displayed by both home and away crowds.
Bayern Munich was fined 40,000 euros and banned from attending Champions League away games for pyrotechnic use on Monday.
The suspension is in force for two years but will be reinstated if there is further fan misconduct.