A Saudi soldier was killed in a cross-border firefight with Yemeni rebels, the interior ministry said Sunday.
A border post was attacked overnight by Houthi rebels, a spokesman said, adding that one soldier wounded in the exchange died before reaching hospital.
He was the latest of at least 111 Saudi soldiers and civilians to die in the country's south since the kingdom launched a coalition to battle Yemeni insurgents in March 2015.
Most Saudi casualties have been from retaliatory cross-border rocket attacks or combat.
But there have also been previous deadly mine blasts in Jazan.
In Yemen itself, more than 7,000 people have been killed, mostly civilians, since March last year according to the United Nations.
A Yemeni military official said Sunday that five rebels were killed in a coalition air raid in the southern Shabwa province.
Also in Shabwa, three armed tribesman were killed in an ambush by fighters belonging to the Yemeni branch of Al-Qaeda.
President Abedrabbo Mansour Hadi Sunday visited the port city of Mukhalla, on Yemen's southeast coast, for the first time since loyalist forces retook it from Islamist militants.