

Yet multiple insurgent groups have claimed responsibility for the bombing, and a senior Pakistani militant told The Associated Press that al-Qaida and Afghan Taliban fighters were also involved in one of the worst attacks in the U.S. intelligence agency's history.
The suicide attack inside the CIA base - which the bomber said was meant to avenge the death of the former Pakistani Taliban leader in a CIA missile strike - could prompt the U.S. to further pressure the government of Pakistan to crack down on militants who operate on both sides of the Afghan-Pakistani border. U.S. missile strikes against targets on the Pakistan side already are on the rise.
Seven CIA employees and a Jordanian intelligence officer were killed Dec. 30 when the suicide bomber detonated his cache of explosives at Camp Chapman, a tightly secured CIA base in Khost province, a dangerous region southeast of the Afghan capital Kabul.
The CIA had cultivated the bomber - a Jordanian doctor identified as Humam Khalil Abu-Mulal al-Balawi - in hopes of obtaining information about al-Qaida's second in command, Ayman al-Zawahri.
Defending his agents, CIA Director Leon Panetta said the bomber was about to be searched before the blast occurred.
"This was not a question of trusting a potential intelligence asset, even one who had provided information that we could verify independently. It is never that simple, and no one ignored the hazards," Panetta wrote in a Washington Post op-ed piece posted online Saturday. "The individual was about to be searched by our security officers - a distance away from other intelligence personnel - when he set off his explosives."