U.S. and allied forces shot down 15 one-way attack drones fired by Iran-backed Yemeni rebels into the Red Sea and Gulf of Aden on Saturday, the U.S. military said.

Shortly afterwards, the rebels claimed the attack, saying they had fired missiles at an "American" commercial ship and launched drones at U.S. warships in "the Red Sea and Gulf of Aden."

It was one of the Houthi’s largest attacks since November, when they began a campaign of drone and missile strikes against vessels in the Red Sea area, vital for world trade, in professed solidarity with Palestinians during Israel's war against Iran-backed Hamas militants in the Gaza Strip.

The U.S. Central Command, or CENTCOM, said the "large-scale" Houthi attack occurred before dawn into the Red Sea and adjacent Gulf of Aden.

CENTCOM and coalition forces determined that the drones "presented an imminent threat to merchant vessels, U.S. Navy and coalition ships in the region."

It added, in a post on social media platform X, that "US Navy vessels and aircraft along with multiple coalition navy ships and aircraft shot down 15" of the drones.

"These actions are taken to protect freedom of navigation and make international waters safer and more secure."

Houthi military spokesperson Yahya Saree, also on X, said the rebels had carried out two separate operations.

The first targeted the commercial vessel Propel Fortune in the Gulf of Aden, he said, calling it an "American" ship.

Vessel tracking websites describe the bulk carrier as Singapore-flagged but did not report its current position.

A second operation fired "37 drones" at "a number of American" warships, Saree said.

The United States in December announced a maritime security initiative to protect Red Sea shipping from Houthi attacks, which have forced commercial vessels to divert from the route that normally carries 12% of global trade.

The rebel strikes this week caused their first reported fatalities.

The Philippine government said two Filipino crew members were among those killed in a missile strike on the bulk carrier True Confidence.

On March 2, the first known vessel sinking from the strikes occurred when the Belize-flagged, Lebanese-operated Rubymar went down in the Red Sea days after a rebel missile strike.

Since January, the United States and Britain have launched repeated strikes on Houthi targets in Yemen in response to the ship attacks, but the rebels have continued to attack merchant vessels and have also targeted American and British ships.

Yemen's rebels control the capital, Sanaa, and much of the Red Sea coast, despite an earlier bombing campaign that a Saudi-led coalition began in 2015 and which continued for years.

On January 9, U.S. and British forces shot down 18 drones and three missiles fired by the rebels toward ships in the Red Sea, the U.S. military said at the time.

Britain said it was the largest attack to that point by the Houthis.