Iran seized an oil tanker named Niovi on Wednesday in the strategic Strait of Hormuz — the narrow mouth of the Persian Gulf through which a fifth of the world's crude oil passes.

It is the second such capture by Tehran in under a week, coming after a series of attacks on shipping in the strategic Gulf waters since 2019. 

What we know so far

Tehran's prosecutor said that the Islamic Revolutionary Guard Corps Navy (IRGCN) seized the tanker following a judicial order after a plaintiff filed a complaint, reported Mizan news agency.

The Greek-owned Niovi was traveling from Dubai towards a port called Fujairah in the United Arab Emirates when IRGCN personnel forced it to change course towards Iranian waters, said the US Navy.

The US has demanded that Iran should "immediately release the ship and its crew." Iran's actions are "contrary to international law," said the US State Department spokesman Vedant Patel. 

Last week Iran seized an oil tanker named Advantage Sweet in the Gulf of Oman.

Ambrey, a maritime security firm, suggested that the seizure of Advantage Sweet was in response to a recent US seizure of an oil cargo aboard the Marshall Islands tanker Suez Rajan. It had allegedly been smuggling sanctioned Iranian crude oil.

Another crude oil tanker in southeast Asia, reportedly smuggling Iranian crude oil, has also been seized by the US.

Tensions over a nuclear deal

Tensions in the Gulf region began after former US President Donald Trump pulled out of Iran's nuclear deal with world powers in 2018 and reimposed crippling sanctions on Iran.

This drastically limited Tehran's enrichment of uranium exchange. In a bid to reduce Iran's energy exports, the harsh sanctions target Iranian oil and petrochemical sales.

Whenever the US has seized Iranian oil shipments, Tehran has responded in a tit-for-tat manner.

The US Navy said Iran has unlawfully seized at least five commercial vessels in the Middle East in the past two years.

"What we are seeing now is the return to a very familiar pattern of US sanctions pressure and Iranian counterpressure" that began during the Trump administration, said Torbjorn Soltvedt, an analyst at the risk intelligence firm Verisk Maplecroft.

An indirect dialogue to revive Iran's nuclear pact with world powers has been stalled since September due to various reasons, including the country's crackdown on popular protests and Tehran's drone sales to Russia.

ns/rc (Reuters, AP, AFP)