Updated

A senior U.S. defense official says an agent for the Central Intelligence Agency was among those killed in a suicide bombing at an Afghan intelligence office — the latest so-called "insider attack" in the war.

The attack Saturday in Kandahar province killed four Afghan intelligence officials and two U.S. intelligence officers. One of the Americans has been identified as a female solider — 24-year-old Brittany B. Gordon, assigned to a military intelligence company from Joint Base Lewis-McChord, Washington.

The official said the other American was an operative working for the CIA. The official spoke on condition of anonymity because he was not authorized to release the information on the record.

NATO says the bomber was a member of Afghanistan's intelligence agency, but the Afghans deny that.

There was no immediate comment from the CIA.