Three Saudis killed and another injured in an explosion in a southern province

Riyadh: A Saudi Arabian security official says three Saudi men have been killed and another seriously wounded in an explosion.

The official says Monday's explosion occurred in the southern Saudi province of Bishah.

The official says the explosion was caused by a projectile that was probably left over by the army, which used to carry out exercises in the desert area.

No other details were immediately available. The official spoke on condition of anonymity because the kingdom's Interior Ministry had not yet issued an official statement on the incident.