Opponents of the Persian Gulf War said yesterday that the death of Iraqi civilians in a U.S. bombing attack had broken the conflict's popular image as an abstract military exercise and condemned the allied air campaign. But congressional supporters of administration policy said that most Americans would accept that the civilian deaths were accidental.

The first highly publicized and documented instance in which a large number of civilians died under U.S. bombs came on the heels of a Soviet initiative aimed at ending the war. Anti-war leaders said that the coincidence of the two events could provide them with their first real opportunity to shift American public opinion, which has so far rallied overwhelmingly to President Bush.

"Today the so-called 'collateral damage' finally assumed a human face as Americans got their first honest look at the war," said Leslie Cagan, coordinator of the National Campaign for Peace in the Middle East. "What we're hoping is that it will remind people that just because you're in a war doesn't mean you can't end a war."

But Sen. Paul Wellstone (D-Minn.), the Senate's most outspoken critic of the war, predicted that most Americans would believe the U.S. claim that the bunker was a military target where civilians happened to be taking shelter and not the Iraqi claim that it was purely a civilian shelter. "When you've got Iraq saying one thing and our government saying another thing, most people believe our government," Wellstone said.

Senator John McCain (R-Ariz.) said that "the American people are mature enough to accept the fact that there will be civilian casualties in war, as tragic as that may be."

And Rep. Stephen J. Solarz (D-N.Y.), one of the staunchest congressional supporters of the administration's policy, said that "even if the Iraqi version of events were true, it hardly proves we were targeting a civilian shelter." He added that the allies' stated policy on avoiding civilian targets stood in contrast to "Iraq's attacks on civilian populations in Israel."

Senator John H. Chafee (R-R.I.), another Bush supporter, said that "for those who were opposed to the war, this will reinforce their view, while those who support the war . . . will understand that this is not something we were trying to do -- not by a long shot."

Nonetheless, Robert J. Lifton, professor of psychiatry and psychology at the City University of New York, said the attack was likely to have a more subtle impact, even if it did not immediately change anyone's mind about the conflict.

"Previous scenes from Iraq showed dead and injured, but not on the scale now being shown," said Lifton, the author of a respected book on Hiroshima. The new images, he said, brought home "what happens with the weapons used in our name."

Lifton said that many Americans might still be inclined to dismiss the pictures, "knowing that these scenes are made available by Iraqi censors. . . . But my sense is that a lot of Americans are left with uneasy questions or at least doubts."

"I've heard people say, 'We're bombing and bombing and bombing,' " said Wellstone, who has called for a pause in the air war. "How can you do that without getting people killed?"

Robert K. Musil, executive director of the Professionals Coalition for Nuclear Disarmament, which opposes the war, said that because of the civilian deaths, "we see the problems of war in very human terms. Up to now, it's been an antiseptic, high-tech, video game war."

But Sen. Paul Simon (D-Ill.), who voted against giving Bush the authority to go to war but now favors prosecuting it to victory, said the impact of the incident might encourage more Arab hostility to U.S. policy.

"In terms of attitudes toward the war, I don't think it affects them greatly in the United States," he said. "In the Muslim world, there will be increasing reaction."

Sen. Bob Kerrey (D-Neb.), a critic of the war, said the episode and the reaction it could unleash in the Arab world should remind the administration that its goals in the war transcend military victory.

"We are trying to stabilize a very important region in the world that has become unstable because of Saddam Hussein," Kerrey said. "The president has defined the objective as the liberation of Kuwait, but that's a means to an end, not the end in itself."