Police in Gibraltar say all four arrested crew members of the Iranian oil tanker seized on suspicion of carrying oil to Syria in violation of European Union sanctions have been freed on bail.
The police said the crew members were released under unspecified conditions but that no charges had been filed, adding that an investigation was ongoing and that the tanker, the Grace 1, continues to be impounded.
All four of the detained crew members were Indian citizens, officials said. The Panamanian-registered tanker carried 28 personnel, mainly Indian, Pakistani, and Ukrainian nationals.
British Foreign Secretary Jeremy Hunt spoke by telephone with Iranian Foreign Minister Mohammad Javad Zarif the same day, saying he had assured his counterpart that Britain would "facilitate release" of the vessel "if we received guarantees that it would not be going to Syria."
"We are being clear to Iran that we are not seeking to escalate this situation," Hunt said before his conversation with Zarif.
Earlier in the day, police in the British territory said that two of the tanker's second mates had been detained following the arrest of the captain and chief officer on July 11.
British Royal Marines on July 4 boarded the Grace 1 off the coast of Gibraltar and seized it over suspicions it was breaking sanctions by taking oil to Syria.
Tehran warned of reciprocal measures if the tanker was not released, with a commander of Iran’s Islamic Revolutionary Guards Corp (IRGC) threatening on July 5 to seize a British ship in retaliation.
On July 11, Britain said three Iranian vessels “attempted to impede” a British oil tanker in the strategic Strait of Hormuz, which connects the Persian Gulf with the Arabian Sea, but backed off when confronted by a British warship.
Iran denied trying to stop the British tanker.
Tehran on July 12 again called on Britain to immediately release the oil tanker.
"This is a dangerous game and has consequences...the legal pretexts for the capture are not valid ... the release of the tanker is in all countries' interest," Foreign Ministry spokesman Abbas Musavi said, according to state news agency IRNA.
Musavi also said "foreign powers should leave the region because Iran and other regional actors are capable of ensuring the regional security."
"Should Britain let itself be influenced and drawn into dangerous games by the U.S., we would advise them to rather not do that," Musavi said.
Fabian Picardo, the chief minister of Gibraltar, told the territory’s parliament that his government decided to seize the tanker "totally independently, based on breaches of existing [EU sanctions] law and not at all based on extraneous political considerations."
"There has been no political request at any time from any government that the Gibraltar government should act or not act, on one basis or another," Picardo said.
Meanwhile, Britain said on July 12 that it was sending a second warship to the Persian Gulf and raising the alert level in the region amid the rising tensions.
Officials said deployment of the HMS Duncan was part of a planned rotation and was designed to ensure a continued British naval presence in the vitally important oil-shipment route.
However, sources told news agencies that the action was brought forward by several days in light of recent actions in the region.
It came as U.S. President Donald Trump stepped up his war of words with Iran, telling Tehran it “better be careful."
"They're treading on very dangerous territory. Iran, if you're listening, you better be careful," he added, speaking to reporters at the White House.