US: Senate Majority Leader Sen Tom Daschle said last night he was "gravely concerned" that the White House had received a warning in August of a possible plot to hijack US planes, and he asked President Bush to turn over to Congress information that he received.
"Clearly there is a lot more to be learned before we can come to any final conclusion about all of the facts, but it clearly raises some very important questions that have to be asked and have to be answered," the South Dakota Democrat told reporters.
"Why did it take eight months for us to receive this information? And, secondly, what specific actions were taken by the White House in response?"
The White House said earlier yesterday it took "all appropriate action" to respond to warnings of attacks on the US which it received last year before September 11th.
"Throughout the summer, beginning in May, the government received heightened reporting on threats to United States' interests or territory, most of it focused on threats abroad," the White House spokesman, Mr Ari Fleischer, said.
"As a result, several actions were taken to button down security," he said, citing security directions to US embassies and military facilities, as well as sharing information about the threats with domestic agencies.
"The President did not - not - receive information about the use of airplanes as missiles by suicide bombers. This was a new type of attack that was not foreseen," Mr Fleischer said.
On Wednesday, the White House said President Bush was told in the months before the September 11th attacks that Osama bin Laden's network might hijack US passenger planes, prompting the administration to issue an alert to federal agencies - but not to the US public.
The revelation that Mr Bush received information about bin Laden's group seeking to hijack US aircraft as early as August has put the White House on the defensive to try to explain why stricter security measures were not taken and why the public was not informed.
Sen John Edwards (Democrat, North Carolina) said on ABC's Good Morning America there were three "enormous red flags" that should have sent alarm bells ringing.
Sen Richard Shelby (Republican, Alabama), vice-chairman of the Senate Intelligence Committee, said he was troubled that the White House waited eight months to make the disclosure.
Members of Congress pointed to warning signs prior to September 11th: the US intelligence Mr Bush received; the fact that an FBI agent had written a memo urging FBI headquarters to investigate Middle Eastern men enrolled in flight schools in the US; and the arrest in Minnesota of Zacarias Moussaoui, who was believed to be training for a suicide hijacking.