The US Coast Guard has seized a tanker it says was smuggling fuel to Cuba, in a sharp escalation of the Trump administration’s oil embargo on the island. The vessel, named Grace, was stopped on September 5 in the Caribbean Sea between Cuba and Mexico. The Coast Guard said it was using tactics common among the ‘dark fleet’, the shadow network of ships that use deceptive practices to dodge sanctions. A Coast Guard team boarded the 300-foot vessel and escorted it to Progreso in Mexico. A Mexican Navy inspection team confirmed large quantities of fuel in the ballast tanks, along with several containers believed to hold illicit fuel. The Coast Guard also announced the seizure of a second Cuba-bound ship, the Jaira Provider, caught on June 28 with more than 200,000 gallons of fuel. ‘The high seas are not a sanctuary for lawlessness,’ said Coast Guard commandant Admiral Kevin Lunday. The blockade, imposed earlier this year, aims to force changes to Cuba’s government. The island faces fuel shortages and long blackouts. Traditional oil supplies from Venezuela and Mexico ended after the US ousted Nicolas Maduro in January, according to Reuters.