The Saudi-led coalition on Monday accused Houthi rebels of hijacking a cargo vessel off the coast of Hudaydah in western Yemen.
In a statement, the coalition said the Houthi militia hijacked a ship carrying medical equipment for a Saudi field hospital on Socotra Island in Yemen.
“This piracy shows the danger posed by the Houthi militia to navigation in the Bab el-Mandeb Strait,” the statement said.
For its part, the British Royal Navy's Maritime Trade Operations (UKMTO) said it received reports of an attack on a vessel near Yemen's port of Ras Isa on the Red Sea.
UKMTO advised ships in the area to exercise extreme caution.
Rebel spokesman Yahya Saree confirmed that the Shia militia had seized an Emirati vessel off the coast of Hudaydah.
Saree said the ship was carrying military equipment and was captured as it "entered the Yemeni territorial waters without license."
The spokesman said further details will be announced during a press conference to be held later.
Yemen has been engulfed by violence and instability since 2014, when Houthi rebels captured much of the country, including the capital Sanaa.
A Saudi-led coalition aimed at reinstating the Yemeni government has worsened the situation, causing one of the world’s worst man-made humanitarian crises, with nearly 80% or about 30 million people needing humanitarian assistance and protection and more than 13 million in danger of starvation, according to UN estimates.