Saudi Arabia said it intercepted seven ballistic missiles fired at Riyadh and other cities by Iranian-backed Houthi rebels in Yemen, the biggest such barrage since the kingdom went to war against them in March 2015. The missiles were intercepted late\u00a0Sunday\u00a0over the northeastern part of the capital and the cities of Najran, Jazan and Khamis Mushait, the official Saudi Press Agency said. Fragments killed one Egyptian national and injured two others in Riyadh, it said, citing the civil defense spokesman, Mohamed al-Humadi. The Houthi-affiliated Saba news agency said the rebels targeted King Khaled International airport in Riyadh, Abha airport in Aseer and Najran\u2019s airport. Rebel leader Abdulmalik al-Houthi said in a televised speech that the group\u2019s missile force is growing and that it enters the fourth year of the war with a \u201cdeveloped rocket system that cannot be intercepted by the U.S. defense systems.\u201d While Iran has rejected Saudi accusations that it supplied the projectiles for previous rebel missile attacks,\u00a0Sunday\u2019s\u00a0barrage could bolster Riyadh\u2019s demands to rein in the Islamic Republic, its arch-rival for regional influence. The assault came as the mastermind of the intervention, Saudi Crown Prince Mohammed bin Salman, known as MBS, tours the U.S. to promote his plan for modernizing and diversifying his country\u2019s economy. Fodder for MBS \u201cThe Saudis have directly blamed the Iranians for previous missile launches, so I expect MbS will bring this up with his U.S. counterparts,\u201d Graham Griffiths, senior analyst at Control Risks Middle East, said in reply to emailed questions. \u201cIt reinforces Saudi claims that measures against Iran need to go beyond a focus on the nuclear issue and address Tehran\u2019s ballistic missile progam and support for armed groups throughout the region.\u201d Washington has armed the kingdom in its intercession in the Yemen conflict, which has created a humanitarian catastrophe with thousands of civilian deaths, disease, hunger and displacement. The prince, who has met with President Donald Trump and other U.S. officials during his visit, designed the intervention in Yemen as part of a broader plan to assert Saudi Arabia\u2019s power more aggressively. The Yemen war is one of several proxy conflicts between the kingdom and Iran across the region. While the kingdom\u2019s allies have been able to recover areas in southern Yemen from the Houthis, the rebels still control the capital Sana\u2019a and territories in the north. The Saudi stock market hardly moved on news of yet another missile attack. The Tadawul All Share Index fell as much as 0.6 percent in Riyadh before reversing to increase 0.1 percent as of\u00a012:41 p.m. \u201cInvestors have priced in already this geopolitical risk, and I don\u2019t think this will have a reversal in their decision to invest in Saudi Arabia,\u201d John Sfakianakis, director of economic research at the Gulf Research Center, said in an email.