NEW YORK - Sheik Omar Abdel-Rahman and his followers plotted to cut a bloody and spectacular swath of destruction across the city in a war of urban terrorism against the United States, a prosecutor said today in his opening statement.

"This is a case about war," Assistant U.S. Attorney Robert Khuzami told the jury. "The enemy is the United States. The battlefield the streets and tunnels of New York City.

"The soldiers who fought this war are seated before you."

Abdel-Rahman and 11 of his Muslim-fundamentalist followers are on trial in the largest terrorism case in U.S. history.

Security at the courthouse was tight, and jitters were evident elsewhere in the city today when an abandoned briefcase on a subway platform prompted transit officials to divert subway service away from Grand Central Terminal for an hour at the height of the morning rush.

Police decided to be extra cautious because of the trial, said transit police spokesman Al O'Leary. The briefcase turned out to be harmless.

Khuzami described the centerpiece of the conspiracy as a plan to set off 12 bombs across the city in one day, targeting the United Nations and tunnels and a bridge linking the city and New Jersey.

"The case is not about religion or about the great issues of the day," Khuzami said. "It's a simple case of men who planned a war of urban terrorism. They planned to slaughter people as they traveled between New York and New Jersey or sat in office buildings while there were ticking time bombs underground."

The defense then began its opening statements. Lynne Stewart, the sheik's lawyer, said: "This prosecution is rotten at its core." The cleric, 56, claims he is being prosecuted for his beliefs.

If convicted, Abdel-Rahman could face life in prison.

Many of the United States' 3 million to 6 million Muslims in the U.S. wish the trial would disappear, and along with it the negative images they fear will follow.

Salam al Marayati, head of the Muslim Public Affairs Council in Los Angeles, predicted: "What will stick in people's mind is the stereotypical, fundamentalist image."

In all, 12 defense lawyers will give opening statements. Then, U.S. District Judge Michael Mukasey plans to tell the jurors that if someone breaks the law, "the fact that it is undertaken in the name of religion is no defense whatsoever."

A preliminary draft of his instructions also say: "There is no religion on trial here."

The trial is the second chapter in the prosecution of a group allegedly responsible for the 1990 assassination of Rabbi Meir Kahane, founder of the militant Jewish Defense League, and the Feb. 26, 1993, World Trade Center bombing, which killed six people and injured hundreds.

Three followers of Abdel-Rahman and a fourth man were convicted in the trade-center bombing last year and were sentenced to life in prison without parole.

Prosecutors said the motive was to punish the United States for supporting Israel.

One defendant in the current trial, El Sayyid Nosair, was acquitted in the 1990 assassination of Kahane but convicted on related weapons charges.

Four months after the trade-center bombing, the FBI said it found five of the defendants now on trial mixing explosives intended for the other targets.

The defendants also allegedly plotted to assassinate Egyptian President Hosni Mubarak and kidnap former President Nixon and former Secretary of State Henry Kissinger. Information from the Chicago Tribune is included in this report