KABUL—The Sept. 11 attacks that triggered the U.S. invasion of Afghanistan also uprooted 16-year-old Abdul Ghattar from his village in war-torn Helmand province, bringing him to a desolate refugee camp on the edge of Kabul.

Yet Mr. Ghattar stared blankly when asked whether he knew about al Qaeda's strike on the U.S., launched a decade ago from Afghan soil.

"Never heard of it," he shrugged as he lined up for water at the camp's well, which serves thousands of fellow refugees. "I have no idea why the Americans are in my country."

In a nearby tent that is the camp's school, his teacher, 22-year-old Mullah Said Nabi Agha, didn't fare much better. He said he has never seen the iconic image of the Twin Towers burning. He was vaguely aware that some kind of explosion had occurred in America.

"I was a child when it happened, and now I am an adult, and the Americans are still here," Mr. Agha said. "I think the Americans did it themselves, so they could invade Afghanistan."