RIYADH - Three Saudi soldiers and an Emirati have been killed on Saudi Arabia’s border with Yemen, where Riyadh is a leading a bombing campaign against Iran-backed rebels, state media said Thursday.

Two Saudi troops were killed at sunset Wednesday when a rocket landed in the Jizan region, the Saudi-led coalition said in a statement carried by the SPA state news agency.

It did not specify the source of fire but cross-border shelling by Yemeni Shiite Huthi rebels has become frequent since Riyadh launched an air campaign against them late March. The statement said a Saudi border guard was also killed at the Alab crossing point in the Asir region, without elaborating.

On Monday, an Emirati soldier died in a border skirmish with Huthi fighters, the statement added.

The UAE is part of the Saudi-led coalition that has been pounding Yemen rebels since March 26 in support of exiled President Abedrabbo Mansour Hadi.

At least 43 people, civilians and troops, have now lost their lives in shelling and skirmishes along the border since the campaign began.

More than 2,600 people have been killed inside Yemen in months of fighting between rebels and pro-government forces.