US President, George W. Bush was told in the months before the September 11 attacks that Osama bin Laden's network might hijack US passenger planes, prompting the administration to issue an alert to federal agencies - but not the American public, the White House said last night.
White House spokesman Ari Fleischer said Mr Bush was briefed on the US intelligence last summer but received no information to suggest that bin Laden's al Qaeda network planned to use airplanes as missiles as they did on September 11 to attack the Pentagon and destroy the World Trade Center.
"Until the attack took place, I think it's fair to say that no one envisioned that as a possibility," Mr Fleischer said.
The disclosure came amid questions about whether US authorities failed to recognise and respond to warnings about possible terrorist attacks prior to the hijackings of the four passenger planes on September 11.
The New York Timesreported that an FBI agent in Arizona had warned his superiors that bin Laden might be sending students to US flight schools.
Washington accuses bin Laden's al Qaeda network of masterminding the attacks, which killed more than 3,000 people.
"There's been a long-standing awareness in the intelligence community, shared with the president, about the potential for bin Laden to have hijackings," Mr Fleischer said. "The information the president got dealt with hijackings in the traditional sense - not suicide bombers, not using planes as missiles."
After the information was presented to Mr Bush, the administration put domestic agencies on alert in the summer, just months before the September 11 attacks, Mr Fleischer said.
That alert was not announced publicly but Mr Fleischer said it may have prompted the hijackers to change their tactics.
"The administration, based on hijackings, notified the appropriate agencies and, I think, that's one of the reasons that you saw that the people who committed the 9-11 attacks used box cutters and plastic knives to get around America's system of protecting against hijackings," he said.
Mr Fleischer did not say which agencies were put on alert and what they did in response.
In contrast, he said the Bush administration did go public last summer with a warning about terrorist threats on the Arabian peninsula.