WASHINGTON - The suicide bomber who killed seven CIA employees at a remote outpost in southeastern Afghanistan had been invited onto the base and was not searched, two former U.S. officials said yesterday.
A former senior intelligence official said the man was being courted as an informant and that it was the first time he had been brought inside the camp.
An experienced CIA debriefer came from Kabul for the meeting, suggesting the purpose was to gain intelligence, the official said.
The former intelligence official and another former official with knowledge of the attack spoke on condition of anonymity.
The CIA would not confirm the details and said it was still gathering evidence on the incident.
A separate U.S. official suggested the bomber may have set off the explosives as he was about to be searched.
The bombing Wednesday dealt a blow to the tight-knit spy agency.
Among those killed was the chief of the CIA post, whom former officials identified as a mother of three.
Six more agency personnel were wounded in what was considered the most lethal attack for the CIA since the war in Afghanistan began in 2001 and possibly even since the 1983 U.S. Embassy bombing in Beirut.
It also was the single deadliest attack for Americans in Afghanistan since eight soldiers were killed in an insurgent attack on a base in the east on Oct. 3.
President Obama and CIA Director Leon Panetta were joined by several lawmakers yesterday in praising agency employees for their work.
"Those who fell yesterday were far from home and close to the enemy, doing the hard work that must be done to protect our country from terrorism," Mr. Panetta said.
"We owe them our deepest gratitude, and we pledge to them and their families that we will never cease fighting for the cause to which they dedicated their lives - a safer America," he said.
In a letter to CIA employees, Mr. Obama said their fallen colleagues came from a "long line of patriots" who had helped to keep the nation safe despite grave risks.
Mr. Panetta said the deaths would not deter the agency.
U.S. State Department spokesman Julie Reside said plans to increase the U.S. civilian presence in Afghanistan remained on track and that security would continue to be a primary concern.
"We fully expected to lose agents, but to lose so many all at once is a huge shock to the system and is very troubling," a former intelligence official said.
According to one former agency employee, the death toll represents a significant portion of the CIA's clandestine force in the region, but that many of the agency's employees have experience in Afghanistan.
"The bench is deeper in Afghanistan than it is anywhere in the world," the former employee said.
The incident occurred at a former military base on the edge of Khost city, the capital of Khost province which borders Pakistan and is a Taliban stronghold.
Taliban spokesman Zabiullah Mujahid said an Afghan National Army officer wearing a suicide vest entered the base and blew himself up inside the gym.
The Afghan Defense Ministry rejected the Taliban's claim that an Afghan soldier was involved in the attack and said none was stationed at the base.
But a spokesman for NATO-led forces in Afghanistan acknowledged Afghan security forces were working there.
Forward Operating Base Chapman used to be a military facility but was later turned into a CIA base, according to a U.S. official.
Mr. Obama has started deploying 30,000 more troops to Afghanistan to tackle the violence and NATO allies are contributing thousands more.
The surge is scheduled to be scaled back, starting in 2011, as the United States gradually hands over security to the Afghans, province by province.