Celtic has been fined by UEFA following their Champions League game against Atletico Madrid on October 25.

This is the third time Celtic has incurred charges from UEFA in their opening three group games.
The fines, totaling £25,000, were imposed for several reasons, with the most significant fine of £15,000 being for a “provocative message of an offensive nature.”
The other fines from the game were for “blocking of public passageways” (£6,900) and “lighting of fireworks” (£3,000). [Football Scotland]
Atletico Madrid also faced a fine for lighting fireworks and received a warning for the improper conduct of the team.
We reported yesterday how Celtic hadn’t received any fines from the match, as it didn’t appear on UEFA’s usual platforms where committee meeting notes are published, but Celtic have since been informed of the fines on Wednesday.
The larger fine against Celtic could well be related to the display of Palestine flags by thousands of fans at Celtic Park ahead of the game. This action occurred amid ongoing conflict in the Middle East between Israel and Hamas in the Gaza Strip. Despite the club urging fans to refrain from bringing any banners or flags related to the conflict, the display went ahead.
In response to these and other behavioural issues, the fan group ‘Green Brigade’ has been banned from attending the stadium by Celtic.