Iran's Adrian Darya 1 oil tanker, which has been at the center of a dispute between Tehran and Washington, was photographed by satellite off the Syrian port of Tartus, the US space technology firm Maxar Technologies Inc. reported on Saturday.

The vessel appeared to have turned off its transponder in the Mediterranean Sea west of Syria, Refinitiv ship-tracking data showed on Tuesday.

The tanker, which is loaded with 2.1 million barrels of crude oil, sent its last signal on Monday, giving its position between Cyprus and Syria, sailing north, the data showed.

Iranian and Syrian officials have not acknowledged the tanker's presence off Tartus.

Iran had guaranteed Gibraltar in writing that the ship "was never destined to an EU sanctioned entity."

US national security adviser John Bolton accused Iran of lying after the emergence of the tanker's satellite images.

"Anyone who said the Adrian Darya-1 wasn't headed to Syria is in denial," Bolton tweeted. "We can talk, but Iran's not getting any sanctions relief until it stops lying and spreading terror!"

At the heart of a US-Iran standoff

The Adrian Darya 1, previously called Grace 1, was detained for weeks by the British Royal Marines off Gibraltar after authorities seized the vessel on suspicion of violating European Union sanctions on Syria. Two weeks later, Iran seized a British-flagged tanker in the Strait of Hormuz leading into the Gulf.

The Iranian tanker was released in mid-August, but the US is still trying to seize it and has warned nations in the region not to assist it.

US President Donald Trump's administration has said it will take action to prevent the Adrian Darya 1 from delivering oil to Syria.

The satellite images showing Adrian Darya 1 off Tartus port come as Iran prepares to speed up uranium enrichment  for its nuclear program, further violating its 2015 deal with world powers. The United States withdrew from the treaty in 2018.

Read more: US blacklists roaming Iranian oil tanker in Mediterranean

Maritime security

Last month, Iran said it sold the oil from the Adrian Darya 1 vessel. Tehran did not identify who bought the 2.1 million barrels of crude oil estimated to be worth $130 million (€117 million).

Government spokesman Ali Rabiei said the buyer of the oil would decide the ship's destination.

After being blocked from docking in Greece, the vessel had been heading for Turkey on August 24.

Meanwhile, the US Transportation Department's Maritime Administration issued a new warning to shippers on Saturday about a potential threat off the coast of Yemen in the southern Red Sea.

"A maritime threat has been reported in the Red Sea in the vicinity of Yemen," the warning read. "The nature of the event is potential increased hostilities that threaten maritime security."

On July 4, British Royal Marine commandos led an operation to seize the tanker on suspicion that it was violating EU sanctions on shipping oil to Syria. The seizure of the supertanker also heightened international tensions in the Persian Gulf.

Most of the crew members were Indian and Pakistani nationals. Iranian officials demanded the immediate release of the tanker on July 5. In a statement, the Foreign Ministry described the UK government's capturing of the ship as "unacceptable."

Later in July, Iran seized two vessels in the Strait of Hormuz, the one sailing under a British flag and another bearing the banner of Liberia. "These seizures are unacceptable," said Jeremy Hunt, Britain's foreign secretary at the time. He warned of "serious consequences" if the issue were not resolved quickly. Iran is still holding the British-flagged ship.

shs/aw (AP, Reuters)

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