DUBAI — A United Arab Emirates oil tanker traveling through the Strait of Hormuz stopped in Iranian waters and switched off its transponder more than two days ago, according to shipping tracking data, amid heightened tensions over a spate of incidents involving commercial vessels in the Persian Gulf.
The Panama-flagged Riah stopped transmitting its position late Saturday and was last shown off the coast of Iran’s Qeshm island in the Strait of Hormuz. It was unclear Tuesday what happened to the tanker, which was on its way to Sharjah in the United Arab Emirates before diverting sharply toward Iranian waters and slowing to a halt, tracking data showed.
A UAE government spokesman did not respond to a request for comment.
Since May, at least six vessels have been attacked near the strait, the world’s most important oil chokepoint, in incidents that the United States has blamed on Iran. Britain said last week that Iranian naval forces attempted to block a British oil tanker traversing the strait but were repelled by a navy frigate escorting the ship.
Iran has denied involvement in the incidents but also threatened to retaliate against British shipping interests after an Iranian oil tanker was seized off the coast of Gibraltar earlier this month.
The vessel, Grace 1, was carrying 2.1 million barrels of light crude oil and was suspected of seeking to travel to the Syrian port of Baniyas in violation of European Union sanctions, authorities in Gibraltar said. Gibraltar is a British territory.
“The vicious British government committed piracy and attacked our ship,” Iran’s supreme leader, Ayatollah Ali Khamenei, said in a speech Tuesday. Iran “will not leave such acts without a response,” he warned.
British Foreign Secretary Jeremy Hunt said Saturday that Britain would help facilitate the Grace 1’s release if Iran could provide guarantees that the ship’s cargo would not go to Syria. Iran has said that it is not subject to E.U. sanctions.
The confrontation comes as Europe struggles to keep Iran in a nuclear deal it struck with world powers in 2015, following a U.S. withdrawal from the pact last year.
The agreement curbed Iran’s nuclear activities in exchange for major sanctions relief, including from the United States. The Trump administration violated the accord and reimposed sanctions on Iran in the fall, prompting Tehran to scale back its own commitments under the deal, Iranian officials said.
European nations have urged Iran to reverse recent moves to breach the agreement, including boosting uranium enrichment levels beyond a limit set by the deal. Iran says it will continue to reduce its obligations to the nuclear pact in 60-day intervals until Europe compensates Tehran for economic losses suffered as a result of U.S. sanctions.
Also Tuesday, Iran’s judiciary confirmed the arrest of French Iranian scholar Fariba Adelkhah, the latest dual national to be detained by Iranian security forces. French President Emmanuel Macron called on Tehran on Monday to explain why Adelkhah, 60, was arrested.
“What has happened worries me a great deal,” Macron told reporters during a visit to Belgrade, Agence France-Presse reported.
“I have expressed my disagreement and asked President [Hassan] Rouhani for clarification,” he said.