US Central Intelligence Agency Director Leon Panetta on Saturday defended the US spy service against criticism following a suicide bombing in Afghanistan, in which seven CIA operatives had been killed. "As an agency, we have found consolation in the strength and heroism of our fallen colleagues and their families," Panetta wrote in an op-ed piece in The Washington Post. "We have found no consolation, however, in public commentary suggesting that those who gave their lives somehow brought it upon themselves because of 'poor tradecraft.'" He said the criticism was akin to suggesting that US Marines who die in a firefight had brought it upon themselves because they have poor war-fighting skills. "This was not a question of trusting a potential intelligence asset, even one who had provided information that we could verify independently," Panetta went on to say. "It is never that simple, and no one ignored the hazards. The individual was about to be searched by our security officers -- a distance away from other intelligence personnel -- when he set off his explosives." A Jordanian doctor said to have been a triple agent blew himself up at a US military base in Khost near the Pakistani border on December 30, the deadliest attack against the CIA since 1983. The Al-Qaeda network hailed the suicide bombing that killed seven CIA agents in Afghanistan as "revenge" for the deaths of top militants in US drone strikes in Pakistan.