On 29 May 2004, a Saturday, four men armed with guns and bombs attacked two oil industry installations and a residential compound, in Al-Khobar, Saudi Arabia—the hub of the Saudi oil industry.[1] Over approximately 25 hours, the gunmen, describing themselves as members of "The Jerusalem Squadron" or "Jerusalem Brigade", killed 22 and injured 25, mainly third country national personnel working in Khobar.[1]