According to The Washington Post, the suicide attack at Combat Outpost Chapman hit a base used by the CIA to target Taliban and al Qaeda operatives in Pakistan and Afghanistan:
The attack represented an audacious blow to intelligence operatives at the vanguard of U.S. counterterrorism operations in both Afghanistan and Pakistan, killing officials whose job involves plotting strikes against the Taliban, al-Qaeda and other extremist groups that are active on the frontier between the two nations. The facility that was targeted — Forward Operating Base Chapman — is in the eastern Afghan province of Khost, which borders North Waziristan, the Pakistani tribal area that is believed to be al-Qaeda’s home base.
U.S. sources confirmed that all the dead and injured were civilians and said they believed that most, if not all, were CIA employees or contractors. At least one Afghan civilian also was killed, the sources said.
It is unclear exactly how the assailant managed to gain access to the heavily guarded U.S.-run post, which serves as an operations and surveillance center for the CIA. The bomber struck in what one U.S. official described as the base’s fitness center.
In addition to the dead, eight people were wounded, several of them seriously, U.S. government officials said.
This explains the initial confusion in the media about the attack. I was privately skeptical about the initial reports from the outset, and suspected there was something bigger going on here. The US military seemed to have little information on the strike and was also reticent to provide additional information. The explanation that the US Embassy was present at the base didn’t make sense: why would the Embassy base such a large number of civilians in Khost, and even if there was such a large contingent in Khost, why base them at Combat Outpost Chapman and not at Forward Operating Base Salerno?
In the bigger picture, this was a major victory for the Haqqani Network. Gathering the intelligence that the CIA was operating from Chapman is no small feat. Getting the suicide bomber into the base and then detonating among a crowd of operatives would have been considered impossible until now. The covert CIA operations are likely going to negatively impacted until the security breach is detected.