Kabul ? The Taliban claimed responsibility today for a suicide bombing at a base in eastern Afghanistan that killed eight American civilians and one Afghan, the worst loss of life for the U.S. in the country since October. A U.S. congressional official said CIA employees are believed to be among the victims.

Four Canadian soldiers and a journalist also were killed Wednesday by a roadside bomb in Afghanistan’s south, the bloodiest single incident suffered by that country’s military this year.

Taliban spokesman Zabiullah Mujahid told The Associated Press that a Taliban bomber wearing a military uniform and a suicide vest entered the base in Khost province Wednesday evening and blew himself up inside the gym. A U.S. official who was briefed on the blast also said it took place in the gym.

That official said eight U.S. civilians and one Afghan were killed; it was not clear if the Afghan victim was military or civilian. Six Americans were wounded, the official said.