Sette baschi rossi (1969)
Sette baschi rossi also known as The Red Berets, Seven Red Berets and Congo Hell is a 1969 Italian/West German co-production about a fictional group of mercenaries filmed in Ethiopia produced and directed by screenwriter Mario Siciliano (often credited as "Marlon Sirko") in his debut as a director. Several of the action set pieces of the film were reused in Siciliano's 1978 Scorticateli vivi/Skin 'em Alive. It was based on the novel Rebellion by Dean Craig AKA Piero Regnoli. Like Dark of the Sun the film also features a train sequence.
More at Wikipedia.