Britain has condemned as "unacceptable" the Iranian seizure of one ship and the apparent brief detention of another as tensions ratcheted up over a spate of dangerous incidents on one of the world's most strategic commercial-shipping routes.
Foreign Secretary Jeremy Hunt on July 19 said he was "extremely concerned" by Iran's actions in the Strait of Hormuz as he called an urgent meeting of senior U.K. security officials "to review what we know and what we can do to swiftly secure the release of the two vessels -- a British-flagged and a Liberian-flagged vessel."
As reports of the seizure of at least one tanker by Iranian forces swirled, the United States accused Tehran of "escalatory violence" and President Donald Trump spoke with French President Emmanuel Macron about the perceived Iranian threat and said he would "talk to the U.K." and "be working with the U.K." in light of the latest developments.
The fresh incidents follow a month of naval confrontations, seizures, and reported shoot-downs of drones involving Iranian and Western vessels, along with accusations and counteraccusations of what happened and who is to blame.
Iran's Islamic Revolutionary Guards Corps (IRGC) on July 19 said it had seized a British tanker, the Stena Impero, in the Strait of Hormuz for an alleged failure "to respect international maritime rules."
Iran's IRNA news agency reported that the tanker had muted its tracker and ignored warnings, a claim that could not be confirmed.
British and U.S. officials said Iran had also seized a second tanker, the Liberian-flagged MV Mesdar.
Tracking services indicated the ship had turned in the direction of Iran, but later changed course and headed back into the Persian Gulf
Iran's semiofficial Fars news agency and the vessel's operator, Norbulk Shipping UK, said guards had seized and boarded the British-operated Mesdar briefly in the Strait of Hormuz. Fars said the ship was given notice to comply with environmental regulations, then allowed to continue on its way.
"These seizures are unacceptable," Hunt said. "It is essential that freedom of navigation is maintained and that all ships can move safely and freely in the region."
The Stena Impero's owner and operator, Stena Bulk and Northern Marine, said in identical statements on their websites that there were 23 seafarers aboard the tanker and that they were unable to contact the vessel. They said there were no reported injuries.
Swedish owner Stena Bulk and operator Marine Management said that they "can confirm that at approximately 1600 BST [1500 GMT/UTC] on 19th July UK registered vessel Stena Impero (built 2018, 49,683 DWT) was approached by unidentified small crafts and a helicopter during transit of the Strait of Hormuz while the vessel was in international waters. We are presently unable to contact the vessel which is now heading north towards Iran."
Vesselfinder.com lists the Stena Impero as a chemica-l and oil-products tanker built in 2018.
The same site says its destination was the Saudi port of Jubail and its estimated arrival was the morning of July 21.
U.K. Chamber of Shipping chief Bob Sanguinetti was quoted as saying the Stena Impero's seizure was a "violation of international regulations which protect ships and their crews as they go about their legitimate business in international waters" and called on the government to do "whatever is necessary" to return the ship and crew to safety. He said it underscored a need for greater security for merchant vessels.
Tensions have been on the rise between Washington and Tehran since Trump last year withdrew from the so-called Joint Comprehensive Plan of Action (JCPOA) to trade sanctions relief for nuclear curbs, although China, Russia, and European powers remained party to it.
Stiff trade and economic sanctions have followed that have dealt major blows to Iran's economy and prompted a war of words between Washington and Tehran.
Iran's reported vessel seizures come with U.S. and Iranian officials still publicly disputing whether a U.S. warship allegedly approached by an Iranian drone in the same strait on July 18 shot down the aircraft.
U.S. Secretary of State Mike Pompeo was quoted during a visit to Buenos Aires on July 19 as urging Iranians to "come to the table" for negotiations, a recurring call since the United States abandoned the landmark nuclear deal.
Less than a month ago, Iranian forces reportedly shot down a U.S. drone that Tehran said was flying over Iranian territory, a claim that Washington rejected.
That incident was said to have prompted Trump to order U.S. forces to prepare for a retaliatory air strike against Iran that was called off at the last minute.
Trump has since called on other countries to condemn what he says are Iran's attempts to disrupt the freedom of navigation and global commerce in the Persian Gulf region, where massive supplies of oil are transported every day.
On July 4, the British Navy seized an Panamanian-flagged Iranian tanker off the southern tip of Spain that it suspected of smuggling oil to Iranian ally Syria in violation of European Union sanctions. On July 19, Gibraltar's government reportedly extended the detention by 30 days of the vessel, the Grace 1.
Iranian state television reported that the IRGC had seized a foreign tanker on July 14 with 12 crew members aboard. State TV reported on July 18 that the tanker was transporting fuel from Iranian smugglers to foreign customers and was intercepted south of Iran's Lark Island in the Strait of Hormuz.
The state TV report did not identify the tanker nor the nationalities of the crew members.