MEXICO CITY — A tip from the United States led to this week's high seas seizure off Mexico's Pacific Coast of a drug-laden semisubmersible submarinelike vessel, Homeland Security Secretary Michael Chertoff said Friday.

Speaking to a small group of U.S. media in Mexico City after spending the morning with Mexican national security officials, Chertoff confirmed intelligence gathered by the U.S. government led to the seizure of the vessel off the coast of Oaxaca state on Wednesday.

"I praised them and congratulated them for the seizure of the semisubmersible sub," said Chertoff, calling the action "a great example of cooperation, between our ability to share intelligence about the vessel and their skill in fast-roping their marines from helicopters and being able to actually seize the vessel before it was sunk."

The vessel, which looks like a cross between a submarine and a cigarette boat, was towed into the Pacific port of Salinas Cruz on Friday, where authorities removed what they said was 5.8 tons of cocaine. The drugs were wrapped in 257 plastic packages.

Jose Ruiz, a spokesman from the U.S. military's Southern Command in Miami, said at least 40 semisubmersible subs have been spotted by the United States and allies since 2006, mostly hugging the Pacific Coast of Central America or Mexico. The U.S. Coast Guard seized one back in November 2006.

The pronounced increase in the use of semisubmersible vessels by Colombian drug traffickers points to the success of stepped up anti-drug efforts in the Caribbean Sea. Traffickers have been forced to move drug loads via Pacific routes that involve more dangerous, easier to spot travel in open seas.

Wednesday's seizure stood out because Mexico was able to grab the green makeshift wood-and-fiberglass submarine before it was scuttled, providing a better sense of how traffickers are designing these odd drug-transport ships more commonly used to ferry drugs in Colombian jungle rivers. The U.S. Coast Guard estimates the cost of building one of the semisubmersible vessels at $2 million.

"I think they are fabricated in South America by the people who are using them," Chertoff said of the vessels, which are mostly submerged when under power and reportedly can travel underwater for short periods of time before rising to take in more oxygen. "I don't know whose bright idea it was, but they don't completely submerge. It's designed to ride low enough that it has very low radar signature."