“The Houthi militias must immediately release the ship, otherwise the coalition forces shall take all necessary measures and procedures to deal with this violation, including the use of force,” Malki said in a statement.

Houthi rebels, who control most of northern Yemen, kidnapped a cargo ship flying the flag of the United Arab Emirates, saying it was involved in ‘hostile acts,’ but the Saudis claimed it was carrying hospital equipment.

The ship was on its way from the Yemeni Red Sea island of Socotra to the Saudi port of Jizan, just north of Yemen, when it was hit just before midnight on Sunday, according to Saudi state news agency SPA, citing coalition spokesperson Brigadier General Turki al-Malki.

Saudi Arabia has led a military coalition fighting the Houthis in Yemen for more than six years.

The alliance has accused the Houthis of assaulting ships in the Red Sea, which leads to the Suez Canal and is one of the world’s busiest maritime corridors.

According to the alliance, the ship was kidnapped off the coast of Hodeidah in western Yemen.

The vessel was transporting military equipment, according to the Houthis’ military spokesman, and was involved in ‘hostile acts targeting the security and stability of the Yemeni people.’

The crew, ‘of different nationalities,’ was still on board, according to the statement.

According to SPA, the vessel was transporting equipment from a decommissioned field hospital.

The UK Maritime Trade Operations (UKMTO) said late Sunday that it had received indications of an attack on a vessel near Yemen’s port of Ras Isa, which is just north of Hodeidah, and that it was investigating.

It was unclear whether this was the same attack.

UKMTO, part of the Royal Navy of the United Kingdom, issued advice at 2150 GMT, 0050 local time, advising mariners to take extreme caution in the region.

It indicated the vessel’s position in the Red Sea at around 23 nautical miles west of the Ras Isa oil port.

In late 2019, the Houthis launched a raid in Ras Isa, briefly seizing a Saudi-flagged ship and two South Korean warships.

Tensions in the region have been high as a result of a shadow war between Iran and Israel, as well as the failure of Iran’s nuclear deal with world powers after then-President Donald Trump unilaterally pulled America from the agreement in 2018.

In Vienna, talks to resurrect the agreement are still ongoing.