The Coast Guard unloaded some 7.5 tons of cocaine confiscated from a drug submarine in Miami Beach on Friday.

The cocaine, worth about $180 million, was captured from a submarine that traffickers had sunk in an effort to elude capture. It was the latest instane of drug traffickers using "narco submarines," vessels used to covertly transport large quantities of narcotics into the United States. Some officials warn that narco subs represent a dangerous development as cartels become more bold and innovative in finding ways to outdo law enforcement. Below are some photos of the confiscated drugs, as well as images of a narco submarine recovered in a previous operation.

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Drugs REUTERS
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An undercover anti-narcotics police officer unloads bags of confiscated drugs at a police station in Panama City August 1, 2011 REUTERS
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Undercover anti-narcotics police unload bags of confiscated drugs at a police station in Panama City August 1, 2011. REUTERS
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Cocaine is displayed on a fishing boat at the port in Portimao July 20, 2011 REUTERS
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Members of the Colombian Navy stand guard on top of a seized submarine built by drug smugglers in a makeshift shipyard in Timbiqui, department of Cauca February 14, 2011 REUTERS
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Colombian Navy personnel escort a semi-submarine, which, according to Colombian authorities, is used to transport illicit drugs, at the Atrato River in Turbo province, near Medellin, June 1, 2009. REUTERS
Coast Guard Medicine