Washington D.C: The U.S. has seized the Olina tanker in the Caribbean, the fifth vessel targeted in recent weeks as Washington steps up efforts to curb Venezuelan oil exports, U.S. officials said on Friday.

The Olina, which according to public shipping database Equasis was falsely flying the flag of Timor Leste, previously sailed from Venezuela and had returned to the region, said an industry source with direct knowledge of the matter.

In a pre-dawn move, marines and sailors from Joint Task Force Southern Spear, launched from the carrier USS Gerald R. Ford, apprehended the Olina in the Caribbean Sea "without incident", the U.S. Southern Command said on X.

"Once again, our joint interagency forces sent a clear message this morning: 'there is no safe haven for criminals,'" it said.

The Olina left Venezuela last week fully loaded with oil as part of a flotilla shortly after the U.S. seized Venezuelan President Nicolas Maduro on January 3, and the vessel was returning fully loaded to Venezuela following the U.S. blockade of Venezuelan oil exports, the industry source said.

"The vessel’s AIS (location) tracker was last active 52 days ago in the Venezuelan EEZ, northeast of Curacao," British maritime risk management company Vanguard said separately.

“The seizure follows a prolonged pursuit of tankers linked to sanctioned Venezuelan oil shipments in the region.”

The U.S. imposed sanctions on the Olina in January last year, when it was named the Minerva M, opens new tab, for what Washington said was it being part of the so-called shadow fleet of ships that sail with little regulation or known insurance.

The M Sophia, another of the tankers that was part of a flotilla of a dozen vessels that left Venezuela earlier this month, was seized by U.S. forces earlier this week.

Three vessels - Skylyn, Min Hang and Merope - all fully loaded and part of the same flotilla that left last week, sailed back to Venezuelan waters on Thursday, according to the industry source.

Seven additional tankers from that flotilla, also fully loaded, were set to return to Venezuelan waters on Friday and Saturday, the person said.

All of the oil on board these 10 tankers is owned by Venezuelan state producer PDVSA, the person added. PDVSA did not immediately respond to a request for comment.

It was unclear whether Washington would take action on the other tankers sailing towards Venezuela.The U.S. blockade of sanctioned Venezuelan oil remains in full effect "anywhere in the world", Defense Secretary Pete Hegseth said on Wednesday.