Yemen's Houthi rebels attacked the Red Sea port of Mokha with a remote-controlled boat packed with explosives on Saturday.
The Saudi-led coalition backing Yemen's government said the boat detonated at dawn after colliding with a pier near a group of ships but caused no casualties or substantial damage.
The attack comes a little over a month after the Iran-backed rebels fired a missile at an Emirati ship carrying medical aid as it was leaving Mokha, injuring a crew member.
"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 coalition said in a statement published by the official Saudi news agency SPA.
The rebels said Saturday's attack was targeting an Emirati military ship arriving from Eritrea's Assab port.
Mokha has been held by pro-government forces since being retaken in February. It lies north of the Bab Al Mandeb strait connecting the Red Sea to the Indian Ocean, a key waterway for international trade.
The port was the first to be reacaptured after pro-government forces backed by the coalition launched an operation to retake Yemen's Red Sea coast from the rebels. The key port of Hodeidah further north is still held by the Houthis.
Also on Saturday, Yemeni officials said that pro-government forces took full control of a key military base known as Khalid Ibn Al Walid, near Yemen's west coast.
The fighting to retake the base from the Houthis, who controlled it for more than two years, has killed dozens on both sides.
Later on Saturday, other officials said that 13 members of the government forces and five Houthis were killed when rebels attacked a military site south of the city of Taez, on the south-west coast.
The rebels control northern Yemen and seized the capital Sanaa in September 2014, supported by members of the security forces loyal to former president Ali Abdullah Saleh.
The Saudi-led coalition, in which the UAE is playing a leading role, intervened in the Yemen conflict in March 2015 to support the internationally recognised government of president Abdrabu Mansur Hadi.
The rebels have carried out a number of maritime attacks since last year, including on US and Saudi warships. In October an Emirati ship used to transport aid and injured Yemenis was hit by what crew members said was a missile before rebels opened fire on the vessel in the Bab Al Mandeb strait. Several of the crew were injured but there were no fatalities.
With reporting from Associated Press