Legia Warsaw will take action against fans who were violent during Wednesday's loss to Borussia Dortmund, but deny there was racist chanting.
Wednesday's Group F clash, Legia's first in the competition in 21 years, began amid a boisterous atmosphere that descended into scenes of violence during the first half.
A group of Legia ultras, dressed in balaclavas, attempted to cross the empty section of seating used to segregate the Dortmund supporters from the home faithful.
Video footage from the Polish Army Stadium appeared to show some of the group using pepper spray against security staff as they tried to intervene.
Legia have since issued a statement in which they vow "strict consequences" for the perpetrators, but insist that claims of racist or anti-Semitic songs are wide of the mark.
The message released via their official website reads: "In connection to the incidents which took place during the UEFA Champions League match between Legia Warsaw and Borussia Dortmund, we state as follows:
"1. The media reports suggesting that Legia fans supposedly shouted 'Jude Jude BVB' are not true. It has been determined that the fans shouted 'Nutte Nutte BVB'. This is a chant offensive to Borussia Dortmund and their fans, sung by fans of other German teams. It does not, however, have any anti-Semitic or racist context.
"Nevertheless, we truly apologise to German and Polish fans of Borussia Dortmund who felt offended.
"2. As to all the people who disrupted public order in the West Stand and in the away fans sector, strict consequences are going to be drawn against them."
Legia, who went on to lose the match 6-0, will likely find themselves in hot water with UEFA over the disturbances.