4 Jewish Students Wounded in Brooklyn Bridge Shooting : Attack: Two Hasids are gravely injured. Motive in assault on unmarked van is not known, but retaliation for West Bank massacre is feared.

NEW YORK — A van packed with Hasidic students was sprayed with gunfire Tuesday on the Brooklyn Bridge, gravely injuring two passengers and triggering a massive police investigation into whether the incident was politically motivated.

Two other passengers were wounded in the attack.

At first, police indicated they believed the shooting was the result of a traffic dispute. But after it was revealed the van was attacked three times at the bridge, authorities did not dismiss the possibility that it was retaliation for the massacre of Palestinian worshipers by an extremist Jew in the occupied West Bank last week.

“Obviously, that’s something you can’t exclude, and the speculation is there,” said Mayor Rudolph W. Giuliani. He stressed, however, that there was no hard evidence at this point linking the shootings and the Mideast massacre.

“The driver of the vehicle (van) says there wasn’t a traffic accident of any kind,” said Chief of Detectives Joseph Borelli, and other top law enforcement officials added they did not believe a traffic argument had sparked the shooting.

In Washington, Atty. Gen. Janet Reno and FBI Director Louis J. Freeh said they were monitoring the situation. The joint FBI/police Anti-Terrorist Task Force in New York City was called into the case.

One of the victims was not expected to live, and the prognosis for a second was highly uncertain, physicians at St. Vincent’s Hospital and Medical Center said.

A gunman opened fire from a blue car three separate times, shooting at least nine rounds into the white unmarked van carrying 14 to 16 Lubavitch Hasids in distinctive hats and side curls, police said.

The attack on the van began at 10:24 a.m. The students were returning to Brooklyn from Manhattan, where they had gone to pray at a hospital in which the Lubavitcher’s 91-year-old grand rebbe, Menachem Mendel Schneerson, had undergone cataract surgery.

Schneerson was taken home by a different route, according to Lubavitcher headquarters.

Police said the incident began just as the van was turning onto a ramp to the Brooklyn Bridge. At first, the van’s driver stopped when he heard popping sounds and realized someone was wounded.

Two of the students got out to inspect the van’s shattered rear window. The assailant’s car drove up and a second round was fired. The two students were uninjured, but “the driver of the van now realized he’s being fired upon and he took off,” Borelli said, leaving the two students on the bridge.

The chief of detectives said the blue car caught up with the van again in midspan, and the gunman resumed fire. When the van reached the Brooklyn end of the bridge, the driver notified a policeman on a motor scooter that he had been attacked. The bridge was closed for several hours after the shooting.

The van had been struck at least five times. Nine 9-millimeter shell casings were recovered, and ballistics tests showed that they came from two different weapons, police spokesman John Miller said. Police still believe there was only one gunman, he said.

Police said they had no confirmed description of the attacker, and witnesses’ descriptions were conflicting.

Giuliani labeled the shooting “horrible and outrageous . . . an attack on all New Yorkers.”

“What we have here is a deliberate attempt to murder four men in a deliberate, wanton way,” the mayor said. “We are trying to determine the motive.”

Police Commissioner William Bratton said that on Monday, members of the Lubavitcher sect had reported to police the license plate of a car they believed was conducting surveillance of their activities. Detectives were trying to determine whether it was linked to the attack even though it was a different model than the dark blue car witnesses said was involved in the shooting.

One of the shooting victims, Aaron Halberstam, 20, had “tremendous brain injury” and his outlook was “very poor,” said Dr. Jesse Blumenthal, chief of trauma at St. Vincent’s Hospital.

Nachum Sosonkin, 18, was in critical condition with a bullet in his brain.

Two other students, 17-year-old Yaakov Shapiro and 18-year-old Levi Wilhelm were listed in good condition.

The attack left the Hasidic teen-agers badly frightened, some in shock.

“We have a lot of young people, quite obviously traumatized,” the police commissioner said.

The Lubavitchers, a Hasidic sect that dates to the 18th Century, have an estimated 100,000 adherents worldwide.