The incidents occurred during Thursday's first qualifying round match in the Europa League against Derry City from Northern Ireland. The unrest led to the match being suspended for a quarter of an hour.
The European Football Association (Uefa) decided on Tuesday to fine CSKA Sofia a total of 55,000 euros, equivalent to approximately 600,000 kronor. In addition, the club is not allowed to sell any tickets for the away match against Qarabag in Azerbaijan on Thursday.
Clips circulating on social media show CSKA supporters making several Nazi salutes while Derry fans hold up a banner with an anti-fascist message.
Derry City are also being fined for crowd disturbance. The club must pay approximately SEK 220,000.
