A US congressional hearing was told last night that three years before the September 11th attacks intelligence agencies had information about a group that planned to fly a plane into the World Trade Center.
The information obtained in August 1998 about the group of "unidentified Arabs" was passed to the FBI and the Federal Aviation Administration.
But "the FAA found the plot highly unlikely given the state of that foreign country's aviation program," said Ms Eleanor Hill, staff director of the joint September 11th inquiry of the House and Senate intelligence committees.
This was one of many details revealed at the first public hearing into intelligence failures by America's spy agencies to detect plans by Osama bin Laden and his al-Qaeda network to conduct the September 11th strike.
Although most of the rising volume of threat reports about an impending attack during spring and summer of 2001 pointed to a strike overseas, some of it suggested targets inside the US, Ms Hill told the hearing.
But none of the threats provided a specific time, date, and place of the attack. "My own view is . . . no one will ever really know whether 9/11 could have been prevented," she said.
Before the September 11th attacks, the CIA had only five analysts assigned full-time to bin Laden's network worldwide, and the FBI's terrorism analytic unit had only one analyst looking at al-Qaeda long-term, she said.