The United States on Monday announced a 10-nation coalition to quell Huthi missile and drone attacks on ships transiting the Red Sea, with Britain, France, Bahrain, and Italy among countries joining the "multinational security initiative."
"Countries that seek to uphold the foundational principle of freedom of navigation must come together to tackle the challenge posed by this non-state actor," US Defense Secretary Lloyd Austin said in a statement.
Iran-backed Huthi rebels have escalated attacks on tankers, cargo ships, and other vessels in the Red Sea, imperiling a transit route that carries up to 12 percent of global trade.
The security coalition, Austin said, will operate "with the goal of ensuring freedom of navigation for all countries and bolstering regional security and prosperity."
It includes the United States, United Kingdom, Bahrain, Canada, France, Italy, Netherlands, Norway, Seychelles, and Spain, Austin said.
Yemen's Iran-backed Huthi rebels said earlier they had attacked two "Israeli-linked" vessels in the Red Sea in solidarity with Gaza, as more companies halt transit through the troubled but vital waterway.
The attacks on the Norwegian-owned Swan Atlantic and another ship identified by the Huthis as the MSC Clara are the latest in a flurry of maritime incidents that are disrupting global trade in an attempt to pressure Israel over its war against Hamas militants.
In a statement, the Yemeni rebels said they had carried out a "military operation against two ships linked to the Zionist entity" using naval drones.
They vowed to "continue to prevent all ships heading to Israeli ports… from navigating in the Arab and Red Seas" until more food and medicine is allowed into Gaza.
But the Swan Atlantic's owner, Norway's Inventor Chemical Tankers, said in a statement the ship was carrying biofuel feedstock from France to Reunion Island.
It said the vessel has "no Israeli link" and was managed by a Singaporean firm, adding that the Indian crew were unharmed and the vessel sustained limited damage.
British oil giant BP became the latest to suspend transit through the Red Sea on Monday, while Taiwan shipping firm Evergreen said it was suspending its Israeli cargo shipments with immediate effect.
Frontline, one of the world's largest tanker companies, also said it was rerouting ships and would "only allow new business" that could be routed via South Africa's Cape of Good Hope.
That route is far longer and uses more fuel.
The Red Sea attacks have forced insurance companies to significantly increase premiums on ships, making it uneconomical for some to transit through the Suez Canal.
Italian-Swiss giant Mediterranean Shipping Company, France's CMA CGM, Germany's Hapag-Lloyd, Belgium's Euronav, and Denmark's A.P Moller-Maersk — the latter accounting for 15 percent of global container freight — have all stopped using the Red Sea until further notice.
The attacks have become "a maritime security crisis" with "commercial and economic implications in the region and beyond," Torbjorn Soltvedt of analysis firm Verisk Maplecroft told AFP.
Monday's attack took place as the Pentagon chief visited Israel after a stop in Bahrain, the home base of the US Navy's Fifth Fleet.
"In the Red Sea, we're leading a multinational maritime task force to uphold the bedrock principle of freedom of navigation. Iran's support for Huthi attacks on commercial vessels must stop," Austin said at a news conference.
On Saturday, a US destroyer shot down 14 drones in the Red Sea launched from rebel-controlled areas of Yemen, the US military said.
Britain said one of its destroyers had also brought down a suspected attack drone in the area.
Rebel spokesman Mohammed Abdul Salam said neutral Oman had launched mediation efforts to safeguard shipping using the waterway.
"Under the sponsorship of our brothers in the Sultanate of Oman, communication and discussion continue with a number of international parties regarding operations in the Red Sea and Arabian Sea," he said on X, formerly Twitter.
The Gaza war broke out when its rulers Hamas launched an unprecedented attack on Israel on October 7, killing around 1,140 people and kidnapping some 250, according to an AFP tally based on official Israeli figures.
Gaza's health ministry says Israel's military response has killed more than 19,450 people, mostly women and children.