The U.S. Coast Guard reported intercepting a ship attempting to smuggle illegal fuel to Cuba.
U.S. authorities believe the vessel was employing tactics typical of the "dark fleet"—ships that use deceptive practices to hide unlawful maritime activities.
In a statement to media on Friday, the Coast Guard said its investigation began in early September when a Coast Guard tactical team boarded the M/V Grace in the Caribbean Sea. The Coast Guard then escorted the ship to Progreso, Mexico. There, a Mexican Navy inspection team uncovered large quantities of fuel stored unsafely inside the vessel’s ballast tanks, alongside several containers believed to hold additional illicit fuel.
"Illicit fuel shipments violate international law and pose severe environmental threats in the Caribbean Sea," said Vice Adm. Nate Moore, deputy commandant for operations, in a statement.
Coast Guard officials the operation was the second major interdiction of its kind this summer, following the earlier detention of the M/V Jaira Provider.
"The high seas are not a sanctuary for lawlessness,” said Adm. Kevin Lunday, commandant of the Coast Guard. “Dark fleet actors who employ deceptive tactics to engage in illicit activities will not evade justice."
The interception of the vessel carrying illegal fuel comes at a time of heightened tensions between the U.S. and Cuba.
READ MORE: President Trump lambastes Cuba as 'failed state' in UN Assembly speech. Cuban delegation walked out
Last Saturday, addressing the United Nations General Assembly, Cuban Foreign Minister Bruno Rodríguez Parrilla accused the Trump administration of carrying out a "ruthless siege" and imposing an illegal "energy blockade" designed to suffocate the island's economy.
The Trump administration has been trying to force changes to Cuba’s political system by cutting off fuel to the island, leading to massive power outages that affect basic activities such as cooking, water supply, and internet and telephone service.
Millions of people have lost access to electricity as Cuba’s power grid has collapsed at least six times since the U.S. energy blockade began at the start of the year. The restrictions prevent Cuba from importing fuel needed to operate its thermoelectric power plants or replacement parts to maintain infrastructure that in many cases has become obsolete.
Rodríguez said other sanctions and commercial pressures have left more than 7,000 shipping containers stranded in international ports. These shipments, many of which contain critical medicines, medical supplies, and food paid for by private Cuban firms, remain unable to reach the island.
Trump, speaking to U.N. General Assembly on Sept. 28, branded Cuba an "absolutely failed state" and said the island's communist government "will fall" under mounting economic and geopolitical pressure. The Cuban delegation walked out during the speech.
