NEW YORK -- The suspects in the World Trade Center bombing sent a letter around the time of the attack that claimed responsibility and attributed the action to deep resentment against U.S. policy in the Middle East, law enforcement officials said yesterday.
The officials said they had determined late last week that the letter from a group calling itself the Liberation Army Fifth Battalion was authentic and that it provided the first insight into what might have prompted the attack.
The letter, mailed to the New York Times four days after the bombing and turned over to the authorities, warned of additional actions against American civilian and military targets, including what they described as "nuclear targets." Such attacks, they said, would be forthcoming unless the United States met a series of demands, including an end to diplomatic relations with Israel and an end to interfering "with any of the Middle East countries interior affairs."
The claims and threats were contained in a letter that described deep resentment over U.S. policies in the Middle East and said that Americans themselves were responsible.
"The American people must know, that their civilians who got killed are not better than those who are getting killed by the American weapons and support," said the letter, which was written in occasionally faulty English.
"The American people are responsible for the actions of their government and they must question all of the crimes that their government is committing against other people," it continued. "Or they -- Americans -- will be the targets of our operations that could diminish them."
Federal investigators said they determined late last week that the letter was "authentic" and that it had been prepared by one of the five men now in custody, law-enforcement officials said yesterday. But the officials declined to say precisely how the determination had been made, saying that it could compromise the investigation.
The four charged thus far in the bombing are: Mahmud Abohalima, 33, extradited from Egypt after fleeing there and portrayed as the mastermind; Mohammed Salameh, 25, who is accused of renting the van used to carry the bomb in the parking garage under the trade center; Nidal A. Ayyad, 25, a chemical engineer; and Bilall Alkaisi, 27, who walked in alone to the FBI office in Newark, N.J., because he had heard that agents wanted to question him. A fifth man, Ibraham A. Elgabrowny, 42, was arrested after he scuffled with federal agents who had been sent to search his apartment.
All but Mr. Alkaisi have entered pleas of not guilty; he entered no plea and is to have a hearing Tuesday.
The evidence linking the suspect to the one-page letter is "incontrovertible, and it's not speculation," the investigator said. "It's the kind of evidence admissible in court."
The Feb. 26 explosion in the basement garage of the Trade Center killed six people, injured more than 1,000 and caused hundreds of millions of dollars in damage.