http://www.washingtonpost.com/wp-dy...12/30/AR2009123000201.html?hpid=moreheadlines A suicide bomber blew himself up Wednesday inside an Afghan military base used by the CIA, killing at least eight Americans in what is believed to be the deadliest single attack on U.S. intelligence personnel in the eight-year-long war, U.S. officials said. The bomber managed to slip past security at Forward Operating Base Chapman in the eastern province of Khost before detonating an explosive belt in what one U.S. official described as a room used as a fitness center. The blast also wounded eight people, several of them seriously, U.S. government officials said. It was not immediately clear how the assailant was able to infiltrate the U.S.-run post, which serves as an operations and surveillance center for the CIA near the Afghanistan-Pakistan border. U.S. sources confirmed that all the dead and injured were civilians, adding that most of them were probably CIA employees or contractors. At least one Afghan civilian was also killed, the sources said. While many details remain uncertain, the attack appears to have killed more U.S. intelligence personnel than have died since the U.S.-led invasion of Afghanistan began in late 2001. The CIA has previously acknowledged the deaths of four officers in fighting in Afghanistan in the past eight years. "It is the nightmare we've been anticipating since we went into Afghanistan and Iraq," said John E. McLaughlin, a former CIA deputy director who now serves on a board that supports children of CIA officers slain on the job. "Our people are often out on the front line, without adequate force protection, and they put their lives quite literally in jeopardy." The CIA has been quietly bolstering its ranks in Afghanistan in recent weeks, mirroring the surge of military troops in the country. Agency officers coordinated the initial U.S.-led attack on Afghanistan in 2001 and have since provided hundreds of spies, paramilitary operatives and analysts in the region for roles ranging from counterterrorism to counter-narcotics. The agency also operates the remote-control aircraft used in aerial strikes on suspected al-Qaeda and Taliban fighters in the lawless tribal provinces on the Pakistani side of the border. U.S. military officials and diplomats confirmed Wednesday's attack and the eight civilian deaths. "We mourn the loss of life in this attack," State Department spokesman Ian Kelly said. Before Wednesday's attack, the number of U.S. deaths in Afghanistan this year had reached 309, the highest one-year total since the start of the war. Eleven U.S. military personnel have been killed since Dec. 1. Staff writers Karen DeYoung and Michael Shear and researcher Julie Tate contributed to this report.