The Saudi-led coalition backing Yemen's government said Shia Houthi rebels on Saturday used a remote-controlled boat packed with explosives to attack the Red Sea port of Mokha, but without causing casualties.
"On Saturday at dawn, Houthi militiamen targeted the port of Mokha with a remotely guided vessel full of explosives," a statement from the coalition said.
The statement, published by the official Saudi news agency SPA, said the boat exploded by the quayside, without causing any injuries or damage.
"In carrying out such criminal acts, the rebels are disrupting the flow of humanitarian aid to Yemen, in particular medicines used to fight the rampant cholera epidemic," the statement said.
The coalition intervened in the impoverished Arabian Peninsula country in March 2015 to support President Abedrabbo Mansour Hadi, who says the rebels are supported by its regional arch-rival Iran.
The war has killed more than 8,000 people and wounded 44,500 since Saudi Arabia and its allies joined the conflict.
Mokha, held by pro-government forces since being retaken in February, is north of the Bab al-Mandab strait connecting the Red Sea to the Indian Ocean, a key waterway for international trade.
The United Nations said on Wednesday that a vicious combination of war, cholera and hunger has left 80 percent of Yemeni children in desperate need of aid.
The cholera outbreak has already claimed more than 1,800 lives since April, with 400,000 suspected cases across the country, according to the UN and the International Committee of the Red Cross.