In 1973, the city was the site of an anomalous hostage crisis in which members of Black September held 10 hostages at the Saudi Arabian embassy, five of them diplomats. The US ambassador, the US deputy ambassador, and the Belgian ''chargé d'affaires'' were murdered. The remaining hostages were released. A 1973 United States Department of State document, declassified in 2006, concluded: "The Khartoum operation was planned and carried out with the full knowledge and personal approval of Yasser Arafat."