The U.S. Coast Guard captured a 40-foot-long submarine carrying 12,000 pounds of cocaine worth more than $165 million in the Pacific Ocean as it made its way to the United States earlier this month, authorities said Tuesday.

Crew members of the Coast Guard cutter Valiant launched two smaller boats that boarded the drug-carrying vessel and captured four suspected smugglers in the eastern Pacific on Sept. 5, officials said.

The capture came with the "assistance of Colombian Naval assets that arrived on scene shortly after," according to the Coast Guard statement. A Coast Guard spokesman declined to reveal any more specific details about where the operation took place.

Bales of cocaine seized from a suspected smuggling vessel lie on the deck of the U.S. Coast Guard Cutter Valiant in September. U.S. Coast Guard

"There are no words to describe the feeling Valiant crew is experiencing right now,” Cmdr. Matthew Waldron, the cutter’s commanding officer, said in a prepared statement.

“In a 24-hour period, the crew both crossed the equator and intercepted a drug-laden self-propelled semi-submersible vessel. Each in and of themselves is momentous events in any cutterman's career. Taken together, however, it is truly remarkably unprecedented. This interdiction was an all-hands-on-deck evolution, and each crew member performed above and beyond the call of duty."

The four captured men — Enrique Mantilla-Olaya, Fausto Hurtado-Candelo, Wiber Tenorio-Rodriguez and Fernando Tribino-MIna — are being prosecuted by the U.S. Attorney's Office in Tampa. They've each been indicted with two counts of possession with intent to distribute cocaine.

It was not immediately clear from which country the submarine originated.

All four defendants used Spanish language interpreters in legal proceedings, according to court documents. Tenorio-Rodriguez is a citizen of Colombia, said his lawyer, who declined further comment.

Lawyers for the other three defendants did not immediately return messages seeking their comments on Tuesday.

In June, the Coast Guard seized another narco-sub in the eastern Pacific with 17,000 pounds of cocaine in a daring capture caught on video.

That bust was one of 14 drug-smuggling vessels intercepted off the coasts of Mexico, Central and South America by three Coast Guard cutters between May and July.

A total of 39,000 pounds of cocaine and 933 pounds of marijuana were seized in those three months, for an estimated worth of $569 million, officials said.