A Saudi armed forces statement said the five soldiers were killed on Sunday in the southwest region of Najran, while the helicopter crashed on Sunday due to a technical defect in the Taif area, killing its pilot. 

Saudi Arabia is leading a coalition of mainly Persian Gulf nations fighting the Yemeni Houthis who controled Yemen's capital, Sana'a, last September and in March the Saudi-led coalition began a campaign of airstrikes against them.

Meanwhile, one Emirati serviceman was killed in the ground offensive in Ma'rib, the United Arab Emirates state news agency WAM said late on Sunday, Reuters reported.