By Agence France-Presse

Britain on Friday said Iran had seized two ships in the Gulf, with Foreign Secretary Jeremy Hunt condemning the incidents as “unacceptable” and saying he was “extremely concerned”.

“I’m extremely concerned by the seizure of two naval vessels by Iranian authorities in the Strait of Hormuz,” he said in a statement. “These seizures are unacceptable.”

Britain confirmed that one of the boats seized was British registered.

The other was Liberian-flagged, but reported to be owned by British company Norbulk Shipping.

The government was to hold an emergency ministerial meeting later on Friday “to review what we know and what we can do to swiftly secure the release of the two vessels”, Hunt said.

Britain’s ambassador in Tehran was in contact with Iranian authorities “to resolve the situation”, he added.

The government said it did not believe any British citizens were on board either ship, but called on Iran to let them go.

“It is essential that freedom of navigation is maintained and that all ships can move safely and freely in the region,” said Hunt.

Iran’s Revolutionary Guards announced earlier Friday they had confiscated the British tanker Stena Impero, owned by Swedish shipping giant Stena Bulk, for breaking “international maritime rules”.

Liberian-flagged tanker Mesdar, owned by British company Norbulk Shipping, was then reported to have been seized after deviating sharply from its course in the same stretch of water.