The United States Justice Department announced that federal agents have seized millions of dollars worth of fuel that Iranians were sending to Venezuela in an attempt to avoid U.S. economic sanctions. The seizure was characterized as the largest ever of its kind. 

The petroleum was loaded in four tankers. They were stopped and their cargo handed over to the U.S. authorities near the Strait of Hormuz.

In a statement, the U.S. said that 1.116 million barrels of fuel were confiscated from the foreign-flagged vessels M/T Bella, M/T Bering, M/T Pandi, and M/T Luna. The statement added that the operation was conducted “with the assistance of foreign partners.”

The U.S. Justice Department said that the Iranian military responded after the seizure: “Iran’s navy forcibly boarded an unrelated ship in an apparent attempt to recover the seized petroleum but was unsuccessful.” The U.S. Central Command (CENTCOM) released a video of Iranian Special Operations troops fast-roping from a Sea King helicopter onto a ship identified as the “Wila.”

“We are seeing more and more global shipping fleets avoiding the Iran-Venezuela trade due to our sanctions implementation and enforcement efforts,” State Department spokeswoman Morgan Ortagus said in a statement. “The United States remains committed to our maximum pressure campaigns against the Iranian and Maduro regimes.”

Pending the decision by U.S. courts on the forfeiture of the petroleum products, the proceeds from the seizure would go to “support the U.S. Victims of State Sponsored Terrorism Fund instead of those engaging in terrorism, like the [Islamic Revolutionary Guard Corps],” she added.

Unnamed U.S. officials told the Associated Press that military force was not used in the seizure of the cargo, unlike the failed Iranian response, and none of the ships were physically impounded. However, the United States threatened ship owners, insurers, and captains with sanctions to force them to hand over their cargo.

Hojat Soltani, Iran’s ambassador to Venezuela denied the accusations of the U.S. that the Iranians either owned the ships or had been involved with the seized shipments.

“Yet another lie and psychological warfare by the U.S. propaganda machine. The tankers are neither Iranian, nor their owners or flags have anything to do with Iran. The terrorist Trump just wants to cover up the humiliation of his failure against the great nation of Iran by scattering false propaganda,” the ambassador wrote in a post on Twitter.

However, one of the front companies involved in the shipment to Venezuela, the Avantgarde Group, has been linked to the Iranian Islamic Revolutionary Guard and earlier attempts to evade U.S. sanctions, according to American officials.

Al-Jazeera, in a story released earlier stated that “According to the asset forfeiture complaint, an unnamed company in February invoiced Avantgarde for a $14.9m cash payment for the sale of the gasoline on board the Pandi. Nonetheless, a text message between Madanipour and an unnamed co-conspirator suggest the voyage had encountered difficulties.”

It is unknown where the ships are currently located as several weeks ago their captains turned off the ships’ tracking devices to hide their locations.

Earlier this year, the Venezuelans openly celebrated the arrival, in contravention of U.S. sanctions, of four tankers-worth of Iranian gasoline.

Venezuela holds massive petroleum reserves. But corruption, socialist government mismanagement, and a crumbling economy have crippled the production of refined gasoline. The country has seen its overall crude production sink to the lowest in over seven decades.