Iyman Faris, a Kashmir-born truck driver in Ohio, has been sentenced to 20 years in prison for plotting with the Al Qaeda to blow up New York's Brooklyn Bridge and launch an attack in Washington.

The District Court in Alexandria (Virginia) sentenced Faris after a federal judge rejected his attempt to withdraw his guilty plea.

Faris told the court on Tuesday that he was only trying to fool the Federal Bureau of Investigation when he pleaded guilty on May 1 because he wanted to gather material for a book.

US District Judge Leonie M Brinkena rejected the attempt, which included revelations that Faris had started banging his head against a steel door during an interview with the FBI at the Alexandria Jail. A psychiatric report sought by his lawyer later found he had no mental illness.

Faris told the judge Tuesday that he was innocent. "I don't have any connection to Al Qaeda except my best friend worked for Al Qaeda," he said.

"You have every right to punish me because of my stupidity that day (when he pleaded guilty). I was depressed."

Faris's guilty plea was unsealed June 19, when Attorney General John Ashcroft said he appeared to be a hardworking truck driver but "had a secret double life" that included carrying cash for the Al Qaeda, providing Osama bin Laden with information about ultra-light aircraft and scouting equipment for sabotaging railway tracks and bridge cables.

Officials said Faris was an Al Qaeda scout who had planned with its top operative Khalid Sheikh Mohammed to sever the cables of the Brooklyn Bridge and to derail trains in or near Washington.

Court papers say Faris scouted the bridge and, after concluding the plot would fail, sent a coded message to the Al Qaeda this year that "the weather is too hot".

Paul J McNulty, the US attorney in Alexandria, called the jail sentence "a significant accomplishment in our mission to prevent terrorist attacks in the United States".

On Faris's contention about gathering material for a book, McNulty said: "He did some very serious things. Like most criminals, when they are caught, they have a number of ideas to get themselves out of accountability."