The killing was the latest in a series of attacks on officials and politicians in the impoverished Arabian Peninsula state.

"Gunmen opened fire at the Saudi diplomat's car in a neighbourhood in southern Sanaa, killing him and his Yemeni bodyguard," a Yemeni security official said.

He said the diplomat was the assistant military attache at the Saudi embassy.

A spokesman for the Saudi Foreign Ministry in Riyadh confirmed the killing of the diplomat, and said the ministry would issue a statement shortly.

Restoring stability in Yemen is an international priority because of its strategic position adjoining oil exporter Saudi Arabia as well as major shipping lanes.