The seizure of an Iranian oil tanker by British marines has become the latest high seas escalation involving the Middle East and the West.
The Grace 1 was reportedly boarded by Royal Marines off Gibraltar early Thursday (July 4).
In a statement, the government there said it believed the ship was carrying Iranian oil to a Syrian refinery.
(SOUNDBITE) (English) CHIEF MINISTER OF GIBRALTAR, FABIAN PICARDO, SAYING: "In fact, we have reason to believe that the Grace 1 was carrying its shipment of crude oil to the Banyas refinery in Syria.
That refinery is the property of an entity that is subject to European Union sanctions against Syria." If the oil is confirmed to be Iranian that would mean the shipment also violates U.S. sanctions.
Iran has responded furiously, calling the seizure 'illegal'.
On Thursday it summoned the British ambassador to Tehran to explain.
Experts say Britain almost certainly acted following a request from the U.S. - adding to its tensions with Iran.
Spain isn't happy either.
It doesn't recognise British rule over Gibraltar, and says the incident happened without its authority.
(SOUNDBITE) (Spanish) SPAIN'S ACTING FOREIGN MINISTER JOSEP BORRELL, SAYING: "It was a demand by the United States to the United Kingdom and we are looking into how it affects our sovereignty because it happened in what we understand to be Spanish waters." Refinitiv Eikon mapping shows the ship making a circuitous journey around southern Africa, instead of via the Suez canal.
The Grace 1 was documented as loading Iraqi oil in December.
But there's no record in Iraq of it being in port, and the vessel's tracking system was switched off at the time.
It later reappeared, fully loaded, near an Iranian port.