A Danish supporter brought with him a rainbow flag which he held up at the arena in Baku.
The flag must have been seen in the stands during the warm-up before the match.
Two security guards must then have moved in and seized the flag, according to AP.
Uefa announced yesterday that sponsors may not use marketing with rainbow motifs at matches in Baku and St. Petersburg.
Big discussions
Rainbow flags and similar motifs have aroused great discussions during the European Football Championship. Hungary recently clubbed through anti-LGBTQ laws - and in response to this, the German team captain Manuel Neuer wanted to wear a captain's armband with a rainbow motif when Germany played against Hungary. In addition, Munich, where the event took place, wanted to illuminate the match stadium Allianz Arena in the colors of the rainbow. Uefa said no to this.