Loud bangs caused by fireworks were heard outside Bayern Munich's team hotel in Norway in the early hours of Tuesday ahead of their Champions League match against Vikings FK, the Bild newspaper said.
According to the report, unknown individuals set off fireworks near the hotel at around 1:15 am (2315 GMT) and the action lasted for two minutes.
The upper floors of the ten-story, four-star hotel in the heart of the Norwegian city of Stavanger were also said to have been affected. According to the report, no police or security forces were called.
Bayern are seeking their second win in as many games in the Champions League after opening their campaign with a 5-0 victory over Bodø/Glimt.
Bayern coach Vincent Kompany has to prepare his team for an unfamiliar situation: the Bavarians will play a match on artificial turf only for the second time, according to the club. The previous match, a 2-2 draw against Spartak Moscow, took place on November 22, 2006.