Two soldiers from Saudi Arabia have been taken prisoner by Shiite Houthi rebels in Yemen, according to the Saudi defense ministry.

Brig. Gen. Ahmed bin Hassan Asiri, a spokesman for the Saudi-led coalition in Yemen, said the soldiers "lost their way inside the Yemeni territories" and that evidence points to them "being alive and detained by the Houthi militias," according to the Saudi press agency.

The BBC reports a man claiming to be a Saudi soldier appeared on a pro-Houthi television channel days ago and said he was being held with several comrades.

The soldiers are the first officially announced coalition troops held captive by the Houthis since Saudi Arabia began leading an international bombing campaign against the rebels in late March.

Asiri said the Houthis were responsible for the soldiers' lives and called on the rebels to respect the Geneva Convention. He asked them to not publish pictures of the soldiers and is reported to have assured the men's families that the coalition was doing everything it could to facilitate their release.

On Sunday the Houthis released six foreign hostages captured months ago, including three Americans, two Saudis and a British national.

Saudi Arabia's announcement comes the same day formerly exiled Yemeni President Abdu Rabbo Mansour Hadi arrived in the southern port city of Aden for the first time since he fled to Riyadh nearly six months ago -- and coincides with reports of Saudi-led coalition airstrikes killing at least 20 people in Yemen's capital, Sanaa.Fred Lambert