The CIA has disclosed it failed to properly vet a Jordanian double agent before he carried out a suicide bombing at a CIA base in Afghanistan last year. The attack by Humam Khalil al-Balawi killed seven CIA agents and contractors, the worst for the agency since the 1983 bombing of the US embassy in Lebanon. An internal probe found that a CIA officer in Jordan failed to report warnings that al-Balawi may have been working for al-Qaeda. Balawi was allowed access to the CIA base after claiming he had information to give to the CIA related to the whereabouts of al-Qaeda deputy Ayman al-Zawahiri.