American International Pictures (AIP) bought the US rights of the movie. For American audiences they cut out about 3 minutes of violence and offensive content, changed the dubbing, the voiceover at the start of the film and the music. This US AIP version, running 83 minutes, was called Black Sunday. The original European version of the film, running just over 86 minutes, is called in English The Mask of Satan (reflecting the original Italian title La Maschera del Demonio). The differences between the two versions (using the US and UK DVDs) are detailed here.
To confuse matters this Australian Blu-ray release from Shock Entertainment is called Black Sunday but it is in fact the longer 86 minute European The Mask of Satan cut of the film, and this is the title shown in the credits. Thus, we have the uncut version of the film.