One of the Sept. 11 hijackers boasted that he would kill thousands in an attack on the World Trade Center nearly a year and a half before he crashed an airplane into the south tower, Germany's chief prosecutor revealed Thursday.

"There will be thousands of dead. You will all think of me," Marwan Al-Shehhi, a member of a Hamburg terror cell, told a librarian in April or May of 2000.

Outlining the Hamburg cell's role in the Sept. 11 attacks in the greatest detail yet, chief German prosecutor Key Nehm said the hijackers knew by October 1999 they would attack the United States with airplanes -- but said the idea likely originated elsewhere in the Al Qaeda network.

The details, which give the clearest indication so far that the members of the Hamburg cell were aware of the scope of their mission, are contained in a 90-page indictment against Mounir El Motassadeq, 28, the only person in German custody in connection with the attack.

Germany has issued international warrants for three other cell members, fugitives Ramzi Binalshibh, seen in Malaysia in June 2001, Said Bahaji, who left Germany eight days before the attacks, and Zakariya Essabar.

The indictment charging El Motassadeq with belonging to a terror group and 3,000 counts of being an accessory to murder remained sealed. But Nehm described in detail how the cell was formed and how its members received training, orders and financing.

"All the members of this cell shared the same religious convictions, an Islamic lifestyle, a feeling of being out of place in unfamiliar cultural surroundings," Nehm said. "At the center of this stood the hatred of the world Jewry and the United States."

Prosecutors said El Motassadeq, a Moroccan man who was arrested in Hamburg two months after the attacks, maintained the cell's logistics along with Binalshibh after the hijackers went to get flight training in United States. Prosecutors expect his trial to begin by the end of the year in Hamburg superior court.

"He said the Nazi's mass murder of the Jews was good and he approved of terrorist attacks, as well as using violence as a way to convert to Islam," Nehm said, quoting from the indictment based on information gathered in nearly a year of witness interviews in Hamburg and other evidence, including terror suspect Kamel Ressam's testimony to U.S. authorities.

The seven known members of the Hamburg cell -- including hijackers Mohammed Atta, Ziad Jarrah and al-Shehhi -- arrived as students in Germany from 1992-97. By the summer of 1999, they had coalesced into a terror cell, described by Nehm as a "closed, conspiratorial group" with the goal of extending the Holy War to the West, especially the United States.

A month after settling on using airplanes to attack the United States, the three hijackers and Binalshibh traveled to Afghanistan to discuss details with Al Qaeda leadership, receive military training and secure financial and logistical support, Nehm said.

Though El Motassadeq denied any involvement in the terror cell, Nehm said he was a key member, preparing logistics for the group. El Motassadeq received military training in Afghanistan from May-August 2000 in Afghanistan, and was observed at an Al Qaeda guest house and training camp near Kandahar.

Later, he transferred funds from al Shehhi's Hamburg account to pay for flight school for al-Shehhi and Atta. Al-Shehhi had granted him power of attorney over the account, which was replenished periodically with infusions from the United Arab Emirates, Nehm said.

El Motassadeq left Morocco in 1993 to study German in the western city of Muenster, Nehm said. While there, according to a recent report in Der Spiegel, he worked in a restaurant owned by the family of a man killed in the trade center attacks -- meeting the victim on at least one occasion.

Shortly after arriving in Hamburg to study electrical engineering at the Technical University in 1995, El Motassadeq met Atta. He quickly gained his trust, and the following year signed the hijacker's will.

"The will demonstrated that one was ready to give his life for the holy war," Nehm said.

Leaving El Motassadeq to run things in Hamburg, Atta, Jarrah and al-Shehhi departed for the United States in mid-2000 to begin their flight training at schools in Florida.

Binalshibh was foreseen as the fourth pilot, Nehm said, but he was unable to get a U.S. visa. Essabar, whom El Motassadeq met at Hamburg's al-Quds mosque in 1997, was nominated to replace him, but also failed to get a visa.

In their place, Zacarias Moussaoui flew to the United States in February 2001, Nehm said. He was arrested the following August after a flight school became suspicious, and is on trial in Virginia on charges of conspiracy to commit terrorism and murder federal employees.

According to Nehm, Moussaoui met with Binalshibh in London in December 2000, and Binalshibh transferred $11,290 to the United States to pay for his flight lessons.

In the months before the attacks, the members of the cell continued to meet in Europe, Nehm said. Atta and Binalshibh met in both Berlin and Tarragona, Spain and Jarrah traveled to Germany at least six times between January and July 2001.