'Scrambled fighters arrived too late'

US Air Force jets were scrambled to intercept the hijacked jets but arrived too late, according to reports.

Pentagon sources have revealed at least four fighters took off from bases in Massachusetts and Virginia.

It is said the fighters arrived a few minutes after the second airliner crashed into the World Trade Centre and the third into the Pentagon.

Two armed F-15s took off at 8.52am EDT (1.52pm Irish Time) on Tuesday from Otis Air National Guard Base in Falmouth, Massachusetts - about six minutes after American Airlines Flight 11 out of Boston crashed into the Trade Centre's north tower.

The fighters raced toward New York but didn't arrive until after the second airliner crashed into the second tower.

In the attack on the Pentagon, sources say two F-16s left Langley Air Force base in southeast Virginia at 9.35am EDT (2.35pm Irish Time) - just two minutes before American Airlines Flight 77 crashed into the military headquarters.

Sources say the FAA did not request any action in regard to United Airlines Flight 93, which crashed in Pennsylvania.

Deputy Defence Secretary Paul Wolfowitz has said the Pentagon was tracking the fourth airliner and could have brought it down if President Bush had decided it was necessary.

He said: "I think it was the heroism of the passengers on board that brought it down, but the Air Force was in a position to do so if we had to."