Looking for a movie from late 70's early 80's about jewel smuggling maybe out of Central or South America.

Looking for a movie from late 70's early 80's about jewel smuggling maybe out of Central or South America. The only part I remember is people getting gunned down in a jungle by a train car because some stolen jewels were found in their canteens." It was really graphic and I was quite young so it stuck out in my mind. I have the name of the movie on the tip of my tongue and it is driving me crazy.

maybe Romancing the Stone? w/ Michael Douglas and Kathleen Turner....
http://www.amazon.com/Romancing-Stone-Michael-Douglas/dp/6300247821

River of Mystery (1971)?

"The beauty and splendor of Rio de Janeiro and the Brazilian countryside provide the backdrop for this adventure story. A crooked, money hungry exiled criminal develops a scheme to make enough money to gain entrance back to the United States. He hires diamond hunter T. J. Mitchell who solicits the services of oil wildcatters Phil and Ernie to transfer enough explosives to an isolated area so they can divert a river and uncover a fortune in diamonds. The trek to the back-roads of Brazil involve a run-in with mercenaries as well as revolutionaries intent on providing water to their people. Mitchell learns he was double-crossed, as the diamonds were planted. But the team of Phil and Ernie go ahead with the explosives mission, as they were only in it for the money. "

Could be the sequel to "Romancing the Stone" called "The Jewel Of the Nile." If you like this kind of movie, I highly recommend "Blood Diamond", with Leo DiCaprio. Excellent