GUATEMALA CITY,  (Reuters) – Guatemala’s navy  captured a makeshift submarine loaded with five tonnes of  cocaine bound for the United States, the Guatemalan military  said yesterday.

The navy, which was working with the U.S. Drug Enforcement  Administration on the operation, stopped the 55-foot (17-meter)  vessel on Friday off Guatemala’s Pacific coast and arrested  four Colombian men on board.

“There was a sleeping compartment, another (compartment)  for the engine, and a third for cargo which was full of  cocaine,” armed forces spokesman Byron Gutierrez told a news  conference.

The four men were taken into custody by DEA agents. Drug cartels ship hundreds of tonnes of cocaine from Latin  America to the United States every year.

In October 2009, a similar submersible was found 108 miles  (175 km) off the Guatemalan coast, packed with 10 tonnes of  cocaine.

The steel-and-fiberglass vessels run partially submerged in  an attempt to evade radar, but traffickers are working on more  sophisticated designs.

Ecuadorean authorities recently discovered a  nearly-finished craft that would have been the first drug  smuggling submarine to travel completely under the water.