State media in Saudi Arabia are reporting that a land mine has killed a border guard along the kingdom's frontier with Yemen, where it is leading a coalition battling Shiite rebels.

The Saudi Press Agency said late on Monday that the blast also wounded three other border guards in the kingdom's southern Jazan province.

Sporadic cross-border shelling has killed and wounded civilians in Saudi Arabia since the Saudi-led coalition started its Yemen campaign in March 2015.

Since the war against Yemen's Shiite rebels known as Houthis began, more than 6,000 people in Yemen have been killed. The United Nations says more than 80 percent of Yemenis are in dire need of food, water and other aid as a result of the conflict in the Arab world's poorest country.