Iran said it attacked more than a dozen vessels trying to pass through the Strait of Hormuz on Wednesday, as fresh fighting with the United States drove oil prices above $100 per barrel. The attacks came with the six-month war between the United States and Iran deadlocked, as Tehran chokes off the strategic Strait of Hormuz and Washington presses a counter-blockade of Iranian ports.

Iran's Revolutionary Guards said on Wednesday they attacked two US vessels, eight oil tankers, and 10 "non-compliant vessels" that were trying to pass through the strait, Iranian state media reported. The United Kingdom Maritime Trade Operations (UKMTO) said on Wednesday "several" vessels in the Gulf of Oman and the Gulf were "subject to disabling fire as part of ongoing military activity in the region".

The Gulf of Oman lies on the Indian Ocean side of the narrow Hormuz strait, which normally carries around a fifth of the world's oil and liquefied natural gas. On Wednesday Iran's Guards for the first time added parts of the Gulf of Oman and the Arabian Sea to a new "prohibited zone" where vessels will be subject to "sanctions", saying that exact coordinates will be announced.

The Guards also said they struck a US military base in Jordan in response to US forces destroying five Iranian oil tankers a day earlier. Iran's foreign ministry condemned the attack on its oil tankers as "an overt threat to regional and international peace and security," saying that they "increase the dangers of tensions in the region".

It said the targeting of US military facilities in the region was "self-defence". The Islamic republic warned of further strikes targeting tankers off the coast of US allies Kuwait and Bahrain. The US military for its part had said it was responding to an Iranian attack targeting an American warship, the second such incident in less than a week.

The international oil benchmark, Brent North Sea crude, breached $100 per barrel on Wednesday as markets worried the conflict would lead to fresh disruptions to oil supplies. The latest round of fighting was triggered after US forces destroyed five Iranian oil tankers on Tuesday, with the US military saying it "directed the crews to abandon ship" before hitting the vessels.

"Iran continues to try to hit US naval ships, and for every time they do that or try to do that, they're going to lose tankers, and I think you'll see that again today," US Secretary of State Marco Rubio told reporters on Tuesday on a visit to Colombia.

Iranian media reported Tuesday that a US missile struck a tanker off the coast of Kharg Island, adding that there were no casualties. Iran has asserted control of the Strait of Hormuz since US-Israeli strikes began the war in February, with traffic through the waterway virtually paralysed.

Tehran requires vessels to obtain permission and pay transit fees before using the strait.

US Central Command confirmed that American forces struck five Iranian "shadow network" oil tankers in the Gulf of Oman and near Kharg Island, stating that intelligence suggested the vessels were used by the Islamic Revolutionary Guard Corps to fund military operations.

While Tehran alleges it launched retaliatory missile attacks against US assets in Jordan and the Strait of Hormuz, the provided text does not verify these specific counter-strikes or the resulting impact on US personnel or vessels.

Brent crude surpassed $100 a barrel following reported U.S. strikes on Iranian tankers and Houthi attacks on Saudi oil facilities, which have further strained the global supply chain. These price increases, which occurred after six weeks of fluctuations since the onset of the Israel-Iran conflict, have raised concerns about broader economic impacts on fuel and transportation costs.

The US attributed the recovery of an unmanned underwater vehicle by Iranian forces near the Strait of Hormuz to a "malfunction," describing the device as an older model not engaged in sensitive operations, while Iranian state media characterized the event as the capture of a modern submarine.

This development occurred amid broader regional hostilities, including reported US strikes on Iranian oil tankers and Houthi attacks on Saudi energy facilities, though independent verification of specific military engagements and casualty figures remains limited.