] Three of four attackers who killed 22 people in the Saudi
] oil city of Khobar were allowed to escape because they
] were threatening to kill 242 people being held as human
] shields, a senior Saudi Interior Ministry official says.
]
] A group connected to the al Qaeda terrorist network
] claimed responsibility for the weekend attacks, saying
] they were intended to show the Saudi government cannot
] protect its oil workers
] The three men fled in a car belonging to a resident of a residential
] complex they had penetrated. They changed cars several times
] and eluded Saudi security forces, the official said.

So they let the terrorist go. Al Qaeda must be backed by the Saudis.

CNN.com - Saudi: Gunmen allowed to escape - May 31, 2004