British Royal Marines in Gibraltar stormed an Iranian ship believed to have been carrying oil to Syria on Thursday, in what authorities said was a violation of European Union sanctions on Syria.

Gibraltar port and law enforcement agencies, aided by the British marines, detained the Grace 1 super tanker early Thursday morning, the territory's chief minister, Fabian Picardo, said in a statement.

Spain’s acting foreign minister, Josep Borrell, said the United States had asked the UK to intercept the ship.

“We have reason to believe that the Grace 1 was carrying its shipment of crude oil to the Baniyas Refinery in Syria,” Picardo said. “That refinery is the property of an entity that is subject to European Union sanctions against Syria.”

The EU imposed a number of financial, trade and transport sanctions against Syrian President Bashar al-Assad’s regime in 2011 in response to “the continuing brutal campaign” against its own people.

A spokesman for Iran’s Foreign Ministry, Abbas Mousavi, tweeted that the British ambassador to Tehran had been summoned over the “illegal” seizure of the oil tanker.

Mousavi later said the “destructive” seizure of oil tanker by UK could increase tensions in Persian Gulf, Iran-run Press TV reported, citing a statement from Mousavi.

Iranian state news, IRNA, said the 300,000-ton carrying capacity ship was boarded by the Royal Marines early Thursday morning.

The incident comes at a time of heightened tensions between the US and Iran. Earlier this week, Iran announced it would stop complying with several parts of the 2015 nuclear deal which the Trump administration withdrew from last year.

The Syrian government has not yet responded to the incident.

Grace 1 is anchored off the coast of Gibraltar, a British overseas territory on the edge of southern Spain.

The United Kingdom’s Ministry of Defense (MOD) welcomed what it called “firm action by the Gibraltarian authorities, acting to enforce the EU Syria sanctions regime.”

On Thursday Picardo thanked “the brave men and women of the Royal Marines, the Royal Gibraltar Police, Her Majesty’s Customs Gibraltar and the Gibraltar Port Authority for detaining the vessel and its cargo.”

“Be assured that Gibraltar remains safe, secure and committed to the international, rules-based, legal order,” he added.

John Bolton, national security advisor to US President Donald Trump, also chimed in with a tweet. “America & our allies will continue to prevent regimes in Tehran & Damascus from profiting off this illicit trade,” he wrote. (CNN)

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