The assault off the rebel-held port city of Hodeida came as government forces backed by the coalition pressed a deadly drive up the Red Sea coast despite mounting international pressure for a ceasefire.
‘A Saudi frigate came under a terrorist attack by three suicide boats belonging to the Houthi militias,’ the coalition said late on Monday without specifying when the incident occurred.
Suicide attacks are uncharacteristic of the Shia Houthi rebels. They are normally the work of Sunni extremists of Al-Qaeda or the Islamic State group.
Although the Saudi warship ‘dealt with the boats,’ one of them ‘collided with the back of the ship and exploded and caused a fire,’ which the crew brought under control, the coalition said..
As a result of the incident, two Saudi crewmen lost their lives and three were wounded, the coalition said, adding the frigate was able to resume its patrol.
In purported video of the attack shown on the rebels' Al-Masirah television website, the stern of a warship exploded in a large fireball.
The rebels claimed responsibility for the attack without specifying how the vessel was targeted.
‘It was hit with precision after an accurate surveillance operation off the western coast,’ a rebel military official said in a statement.
Since it began air strikes in March 2015, the coalition has imposed an air and sea blockade of rebel-held areas.
It has carried out patrols of the Red Sea to prevent what it says is attempted arms smuggling to the rebels by Shia Iran.
Before government forces launched a major offensive on January 7, the rebels controlled virtually all of Yemen's 450 kilometre (280 mile) long Red Sea coastline.
But loyalist forces have since thrust north from the Bab al-Mandab strait where the Red Sea joins the Indian Ocean, overrunning Dhubab district and entering the historic port of Mokha in their biggest advance in months.
There have been heavy losses on both sides. Nearly 370 combatants have been killed, according to medical sources.
- Trapped in a minefield -
Government forces have also pushed south from a small pocket of territory they control around the port of Midi near the Saudi border.
Heavy fighting has raged around both Midi and the inland town of Haradh, leaving 21 government troops and seven rebels dead over the past 24 hours, military sources said on Tuesday.
Loyalist forces launched an assault on rebel positions but found themselves in a minefield where they came under heavy gunfire, a military official said.
‘That is why the death toll was high.’
The offensive comes with President Abedrabbo Mansour Hadi and his coalition backers under mounting international pressure to agree to a UN ceasefire plan.
In a speech to the Security Council on Thursday, UN envoy Ismail Ould Cheikh Ahmed criticised Hadi for rejecting his proposals for a transition that would see him cede much of his power to a vice president who would oversee a government of national unity.
‘President Hadi continues to criticise the proposals without agreeing to discuss them and this will hinder and impede the path towards peace,’ the envoy said.
Foreign diplomats have privately articulated similar concerns about Hadi for months.
The UN has also criticised the coalition air and sea blockade of rebel areas, warning that it is impeding the delivery of desperately needed aid to millions of civilians.
The UN says about 14 million people -- nearly 80 percent of the entire Yemeni population -- are in need of food aid.
