A rocket fired from Yemen killed a three-year-old boy Saturday in the Saudi border region of Najran, a civil defence official said, in the latest cross-border attack by Iran-backed Yemeni rebels. Major Ali al-Shahrani, civil defence spokesman in southwest Saudi Arabia, told reporters a nine-year-old brother of the boy was also wounded when a Katyusha rocket hit their family's home. The attack came a day after rockets fired from Yemen struck a power station in Najran, marking a rare hit on Saudi Arabia's infrastructure after months of periodic bombardment of the area.