RIYADH — Saudi Arabia shot down a Scud missile fired into the Kingdom by Houthis and their allies on Saturday, the Coalition Command said in a statement carried by the Saudi Press Agency. In the first use of a Scud in the conflict, the missile was fired early Saturday morning at the city of Khamis Mushayt in the Kingdom's southwest and was intercepted by two Patriot missiles, the statement said. The coalition responded to Saturday's attack by targeting and damaging the launcher, which was located south of the Houthi stronghold of Saada, it added. Brig. Gen. Ahmed Asiri, spokesperson of the coalition forces and adviser at the office of the minister of defense, said that the Houthi militias out of desperation relied on the Republican Guard of the ousted president Ali Abdullah Saleh for the Scud attack. “The ousted Saleh regime had stockpiled 300 Scud missiles. We have destroyed many Scud missiles that belonged to the Saleh regime,” Asiri was quoted as saying by Al Arabiya. He said, “We will continue to protect the security of Saudi citizens and ensure their safety.” Khamis Mushayt is home to the King Khalid Air Base, the largest such facility in the south. The Scud launch came a day after rebel allies killed four Saudi troops in cross-border attacks. The Houthis and forces loyal to the ousted president Ali Abdullah Saleh launched a ground offensive targeting the Saudi border in Najran and Jazan, which saw the Kingdom fire artillery and launch Apache attack helicopters. Scores of rebel forces were killed in a battle that lasted from dawn to noon Friday, with four Saudi soldiers killed in the fighting. “It was the first confrontation undertaken by Saleh's (Republican) guard, and coalition planes and Saudi Apache (helicopters) undertook ground fire for 10 hours,” said Al Arabiya's correspondent. Saudi Arabia leads a coalition targeting the rebels in airstrikes that began March 26 in support of the country's President Abdrabbu Mansour Hadi. Those strikes have targeted arms caches and Scud missile sites around the country. Yemeni security officials said coalition planes launched at least six airstrikes early Saturday against a Houthi convoy heading toward Saada. Airstrikes also hit a convoy in Amran province.