Brutal scenes kick off Cannes film contest PARIS (Reuters) - A man stripped to his underwear, his mouth covered with duct tape, hangs from an overpass - the brutal opening scenes of the movie kick-starting the main competition for the Cannes film festival. True to the variety on offer at the influential jamboree, the second picture on Thursday began with a shot of a nubile young woman sunbathing topless on a beach, watched by a voyeur. "Heli" by Mexican director Amat Escalante and "Jeune & Jolie" by France's Francois Ozon were the first two of 20 films competing for the event's coveted Palme D'Or award. Director and jury member Ang Lee praised the diversity on offer at the 12-day event on the French Riviera. "There are different political, social issues, different styles, (the) different charm and charisma of certain filmmakers," said Lee, who won the 2013 Oscar for Best Director with his "Life of Pi." I hope that there is something that just wows us. Something that we cannot even verbalize and we'll all look at each other: 'Oh my God, that's a Palme d'Or!' I hope that happens," he told reporters on Wednesday night. "Heli" tells the story of a family dragged into Mexico's violent drug war through the unwitting actions of a 12-year-old girl in love with a young police cadet. Escalante's atmospheric shots of wide Mexican landscapes ultimately give way to stomach-turning scenes of torture. "My characters suffer violent acts and as a result find themselves under tension," Escalante said in an interview in the festival program. In Mexico, everyone lives with a kind of fear in their gut. Ozon's "Jeune & Jolie" is a coming-of-age film featuring actress Marine Vacth in nearly every scene, often nude. We first see Isabelle, 17, with her well-heeled family on summer vacation, where she has sex for the first time with a young man. Months later, she has begun a secret life as a prostitute. "The subject of the film is, above all, what is it like to be 17 years old and to feel your body transforming," Ozon said in an interview. All of a sudden, you assault your body in order to feel something and push the limits. Prostitution was a way to get at this aspect," he added. This year's lineup includes five U.S. movies, the highest number in six years, including Steven Soderbergh's eagerly awaited "Behind the Candelabra" about pianist Liberace, and "Inside Llewyn Davis," the Coen brothers' look at the early Greenwich Village folk music scene. The jury, including famed director Steven Spielberg, Australian actress Nicole Kidman and French actor Daniel Auteuil, will choose the main winner on May 26. The festival opened on Wednesday night with a film not competing for the top prize - Baz Luhrmann's glamorous "The Great Gatsby." Heavy rain did nothing to stop the fans clamoring for autographs from stars Leonardo DiCaprio and Carey Mulligan on the red carpet. Reporting by Alexandria Sage; Editing by Andrew Heavens