Washington ? Two Bush administration officials told lawmakers Thursday they knew before the Sept. 11 attacks that Osama bin Laden might attack Americans, but they don’t remember being warned that terrorists could fly passenger jets into buildings on U.S. soil.

“I don’t recall any warning about the possibility of a mass casualty attack using civilian airliners,” Deputy Defense Secretary Paul Wolfowitz told the House and Senate intelligence committees. The committees are having a joint inquiry examining intelligence failures leading up to the attacks.

Wolfowitz and Deputy Secretary of State Richard Armitage appeared before the committees one day after the inquiry’s staff director, Eleanor Hill, detailed many previously undisclosed warnings of possible terrorist attacks received by intelligence agencies before Sept. 11, 2001. At least 12 involved the use of airplanes as weapons.

On Thursday, the committees examined how top government officials from past and present administrations have used intelligence and to what extent they were aware of the threat bin Laden posed.

“What we had was an emerging threat which we were slow to realize,” Rep. Porter Goss, R-Fla., chairman of the House Intelligence Committee, told reporters after the hearings.

In his written testimony, Armitage said officials “knew that bin Laden had the means and the intent to attack Americans, both at home and abroad.”