The Saudi-led military coalition engaged in Yemen thwarted an "imminent" Houthi attack using an explosives-laden boat south of the Red Sea, Saudi Arabian state media reports say.
A coalition statement carried by state media on Monday said the Iran-aligned movement - which it has been battling for more than six years - continued to threaten maritime channels and global trade.
The Red Sea is one of the world's busiest shipping lanes leading up to the Suez Canal, with thousands of transits made annually through the Bab al-Mandab waterway at its southern tip.
In December, Saudi Arabia said a tanker anchored at the Jeddah port on the Red Sea was hit by an explosive-laden boat, following a separate incident at another Saudi terminal where a tanker was damaged by an explosion.
The Saudi-led coalition intervened in Yemen in March 2015 after the Houthis ousted the internationally recognised government from the capital, Sanaa.
The Houthis, who now control most big urban centres, say they are fighting a corrupt system.
The conflict is widely seen in the region as a proxy war between Saudi Arabia and Iran.