company facility in Riyadh, Saudi Arabia. disclosed and the families of those employees have been notified. one of three compounds attacked. were U.S. citizens and two were citizens of the Philippines. treated and released. Fifteen remain hospitalized, two in serious condition. The identities of the injured people have not been disclosed. the attack. colleagues," said Donald C. Northrop Grumman Mission Systems. deepest sympathy to those who have lost loved ones. and for his support during this difficult time. with the U.S. Vinnell Arabia is under contract to the U.S. services to the Saudi Arabian National Guard. citizens of other countries. U.S. citizens number 300. Vinnell Corporation is part of Northrop Grumman's Mission Systems sector. defense, intelligence and civil government markets.