The Sky Is Falling

The Sky Is Falling, also known as Las Flores Del Vicio, released in the United States as Bloodbath, is a 1975 horror film directed by Silvio Narizzano, written by Gonzalo Suarez, and starring Dennis Hopper, Carroll Baker, Richard Todd, Faith Brook, and Win Wells. The plot follows a group of hopeless American and British expatriates living in a Spanish village where citizens are dying mysterious deaths after the arrival of a strange religious cult.

Synopsis from Wikipedia, CC BY-SA 4.0. Everything below written here.