The British navy said that a group of men who boarded and apparently captured a Panama-flagged vessel yesterday, have now left the ship. The United Kingdom's Royal Navy described the incident which took place in the Gulf of Oman, as a "potential hijacking."

"Boarders have left the vessel," the United Kingdom Marine Trade Operations group said on Wednesday. "Vessel is safe. Incident complete."

The circumstances surrounding Tuesday's seizure of the tanker called Asphalt Princess are murky. The incident has raised concerns of an escalation between the West and Iran.

What we know so far:

The group of men boarded the ship in the Arabian Sea, in an area which leads to the Strait of Hormuz. This is a channel where around a fifth of the world's sea-borne oil gets exported.

London-based media company Argus has reported hearing a recording between the ship and the United Arab Emirates coastguard. The publication said that in that recording, a crew member identified the vessel as the Asphalt Princess and said it had been boarded by five to six Iranians. The crew member apparently did not understand the men and said they should speak to the UAE coastguard.

Oman's Maritime Security Centre confirmed the incident and told the Reuters news agency that suspected Iranian-backed forces were involved. Iran has denied any role in the incident.

Iran's foreign ministry described "successive security incidents involving vessels in the Persian Gulf and the Sea of Oman" as "totally suspicious."

Why is there tension in the region?

Tensions have been simmering since 2018, when the Trump administration in Washington re-imposed sanctions on Iran and abandoned the 2015 nuclear deal between Tehran and five world powers, which also included China and Russia. This led to worsening relations between Iran and the US. In 2019, a series of blasts hit oil tankers in the Gulf of Oman, for which the US accused Tehran of orchestrating.

Just last week, an Israeli-managed tanker was targeted in a suspected drone attack which killed two crew members. The US, Britain and Israel have blamed Tehran for the fatal attack. Iran denied any complicity.

The country's armed forces spokesman, Abolfazl Shekarchi, denounced reports of maritime incidents and hijacking in the Gulf area as "a kind of psychological warfare and setting the stage for new bouts of adventurism."

kb/dj (AP, dpa, Reuters)