The U.S. Coast Guard said it stopped two vessels carrying fuel bound for Cuba in separate operations this year. The agency identified the vessels as Grace, intercepted in early September, and Jaira Provider, stopped earlier in the summer, and described their shipments as illicit.

A Coast Guard tactical team boarded Grace in the Caribbean Sea before the vessel was escorted to Progreso, Mexico. According to the agency, a Mexican Navy inspection team found large quantities of fuel in its ballast tanks. Several containers aboard were also suspected of holding fuel, but the total quantity was not disclosed.

The Coast Guard said its cutters Alert and Charles Sexton supported the operation involving Grace, alongside aircraft and a law enforcement team. It also described Jaira Provider as a substandard vessel carrying illicit fuel to Cuba.

Vice Adm. Nate Moore, the Coast Guard’s deputy commandant for operations, said illegal fuel shipments posed environmental risks in the Caribbean. The agency warned that unsafe fuel storage in ballast tanks and concealed cargoes could increase the risk of spills, threatening coastal communities, fisheries and marine ecosystems.