Bush faces fresh claims he knew of al-Qa'ida attacks before 9/11

Pressure continued to mount on George Bush to explain why more was not done to counter terrorist threats prior to the strikes of 11 September, 2001, as it emerged he was told in the month before of multiple indications of new activities by al-Qa'ida, including plans to hijack aircraft.

Pressure continued to mount on George Bush to explain why more was not done to counter terrorist threats prior to the strikes of 11 September, 2001, as it emerged he was told in the month before of multiple indications of new activities by al-Qa'ida, including plans to hijack aircraft.

The fresh embarrassment for Mr Bush centres on an intelligence briefing he received on 6 August 2001. The page-and-a-half memo, titled "Bin Laden Determined to Strike Inside the United States", was released late last night.

The report said it had not been possible to corroborate some of the "more sensational threat reporting", such as a report in 1998 that bin Laden wanted to hijack a US aircraft to gain the release of those responsible for the 1993 bombing at the World Trade Center.

But the document said the FBI had detected "patterns of suspicious activity in [the US] consistent with preparations for hijackings or other attacks, including recent surveillance of federal buildings in New York."

Mr Bush's national security adviser, Condoleezza Rice, insisted in her public testimony to the 9/11 commission last week that the memo contained mostly historical information and did not warn of any coming attacks inside the US. Her account could be contradicted by the fact that the memo included information from three months beforehand that al-Qa'ida members were trying to enter the US for an attack with explosives.

The document said: "The FBI is conducting approximately 70, full, field investigations throughout the US that it considers Bin Laden-related. The CIA and the FBI are investigating a call to our Embassy in [United Arab Emirates] in May saying that a group or Bin Laden supporters was in the US planning attacks with explosives."

The document gave neither a time nor a suspected target for such an attack. It was based on a May 2001 intelligence report that suggested bin Laden followers wanted to cross from Canada into the US.

"Clandestine, foreign government, and media reports indicate Bin Laden, since 1997, has wanted to conduct terrorist attacks in the US," the document said.

The report said bin Laden's first attempt to strike inside the US appeared to have been a plot at the turn of the century, the so-called millennium plot, when an al-Qa'ida operative entered the US from Canada in an attempt to bomb Los Angeles International Airport.