Federal officials detained fuel shipments worth more than $2.8 million at Port Everglades and the Port of Houston, saying the biodiesel was bound for a sanctioned Cuban company.

Nearly 500,000 gallons were held at the South Florida port, while about 119,000 gallons were seized in Houston. U.S. Customs and Border Protection said intelligence received in early September identified shipments headed to ENETEC, a company on the U.S. Treasury's sanctions list.

Homeland Security Investigations said the shipments appeared to be a coordinated attempt to evade U.S. sanctions. Officials suspect the fuel would have benefited the Cuban government through ENETEC, which they described as state-controlled. HSI Miami chief Jose Figueroa said the shipments involved several companies: 71 shipments at Port Everglades and 19 in Houston.

Officials said the port seizures were unrelated to a separate Coast Guard interception of a vessel carrying fuel to Cuba.