WEST PALM BEACH, Fla. (AP) — The U.S. Coast Guard on Sunday was pursuing another sanctioned oil tanker in the Caribbean Sea as the Trump administration appeared to be intensifying its targeting of such vessels connected to Venezuelan government.

The pursuit of the tanker, which was confirmed by a U.S. official briefed on the operation, comes after U.S. administration announced Saturday it had seized a tanker for the second time in less than two weeks.

The official, who was not authorized to comment publicly about the ongoing operation and spoke on the condition of anonymity, said Sunday’s pursuit involved “a sanctioned dark fleet vessel that is part of Venezuela’s illegal sanctions evasion.”

The official said the vessel was flying a false flag and under a judicial seizure order.

The Coast Guard’s pursuit of the tanker was first reported by Reuters.

Saturday’s predawn seizure of a Panama-flagged vessel called Centuries targeted what the White House described as a “falsely flagged vessel operating as part of the Venezuelan shadow fleet to traffic stolen oil.”

The Coast Guard, with assistance from the Navy, seized a sanction tanker called Skipper on Dec. 10, another part of a shadow fleet of tankers that the U.S. says operates on the fringes of the law to move sanctioned cargo. It was not even flying a nation’s flag when it was seized by the U.S. Coast Guard.

Trump, after that first seizure, vowed that the U.S. would carry out a “blockade” of Venezuela. It all comes as Trump has ratcheted up his rhetoric toward Maduro and warned that the longtime Venezuelan leader’s days in power are numbered.

This past week Trump demanded that Venezuela return assets that it seized from U.S. oil companies years ago, justifying anew his announcement of a “blockade” against oil tankers traveling to or from the South American country that face American sanctions.

Trump cited the lost U.S. investments in Venezuela when asked about his newest tactic in a pressure campaign against Maduro, suggesting the Republican administration’s moves are at least somewhat motivated by disputes over oil investments, along with accusations of drug trafficking. Some sanctioned tankers already are diverting away from Venezuela.

U.S. oil companies dominated Venezuela’s petroleum industry until the country’s leaders moved to nationalize the sector, first in the 1970s and again in the 21st century under Maduro and his predecessor, Hugo Chávez. Compensation offered by Venezuela was deemed insufficient, and in 2014, an international arbitration panel ordered the country’s socialist government to pay $1.6 billion to ExxonMobil.

The targeting of tankers comes as Trump has ordered the Defense Department to carry out a series of attacks on vessels in the Caribbean and eastern Pacific Ocean that his administration alleges are smuggling fentanyl and other illegal drugs into the United States and beyond.

At least 104 people have been killed in 28 known strikes since early September.