Originally posted by the Voice of America. Voice of America content is produced by the Voice of America, a United States federal government-sponsored entity, and is in the public domain. Experts: Saudi Arabia's Sophisticated Defense Vulnerable to Drone Strikes Dale Gavlak AMMAN - The recent attacks on Saudi Arabia's crude oil hub at the Abqaiq and Khurais production facilities reveal that even a nation with a sophisticated military and a massive defense budget is still vulnerable to drone strikes. The United States says satellite images and intelligence information show Iranian weapons were used in the aerial attacks that have shut down half of the kingdom's oil production. Security experts say this latest incident sparks growing concern over the rapid evolution of technologies expanding drones' offensive capabilities. Unidentified U.S. officials have been telling Western media that more than a dozen attacks targeted the installations from a west-northwest direction and not from the southwest as claimed by Iranian-backed Houthi rebels in Yemen who said they carried out the coordinated assault. In July, the Houthis, who are fighting a Saudi-led coalition war in Yemen, showed off their Iranian-made weapons long-range cruise missiles, dubbed "Al-Quds", and explosives-laden "Sammad 3" drones that reportedly can hit targets as far as 1,500 kilometers away. No previous attack, since the Yemen conflict began four years ago, however, has interrupted oil supplies. But the assaults have taken 5.7 million barrels of oil a day off the world's markets. They have also exposed the vulnerability of the pumping heart of Saudi Arabia's oil industry. Defense analysts say the attacks have exposed structural problems in the kingdom's defenses. They say the systems -- albeit sophisticated - are designed to defend against traditional-style attacks -- and not asymmetrical ones from the air by drones. .