For nearly a week the bend at the bottom of Bahar Street had been the unofficial demarcation line between this city and the ring of Israeli armor encircling the Tel Sultan neighborhood to the west. But in less than five minutes on Wednesday afternoon it became a battleground and a new legend in the war between Israel and the Palestinians.

Each side has its own detailed account of how it happened that an Israeli helicopter gunship and a tank opened fire as a procession of Palestinian demonstrators passed through here Wednesday afternoon, killing eight people and wounding dozens more.

Two senior Israeli commanders contend that soldiers were in danger of being cut off from the main force and surrounded by a Palestinian mob sprinkled with armed militants. Soldiers fired a series of warning shots and flares that were ignored by the demonstrators, then four tank shells, also meant as warnings, one or more of which may have ricocheted and inadvertently killed protesters, they said.

But a Palestinian leader who helped inspire and plan the march insisted that all of the participants were unarmed civilians who hoped to call world attention to the plight of their beleaguered neighbors in Tel Sultan and were deliberately cut down by soldiers.

Both sides have used their versions to buttress their cause and blame the other for the damage and the deaths during Israel's incursion into Rafah, in which 42 Palestinians were killed and dozens wounded. Residents whose streets and houses have undergone two years of urban warfare between soldiers and militants are convinced Israel is seeking to expel or exterminate them or render them homeless and destitute.

Army officials concede the war has inflicted major damage on civilians but insist Palestinian militants are responsible because they use the city as a base for smuggling weapons over the border from neighboring Egypt and invade civilian homes to use them as staging grounds and sniper's nests for attacks on soldiers. The militants use women and children as human shields and booby-trap roads and houses, the Israelis contend, then wage propaganda war against Israel when it seeks to root out the gunmen.

"In this kind of war there are always two versions and two separate realities," said Yossi Alpher, an Israeli military analyst and co-founder of Bitterlemons.org, a Palestinian-Israeli Internet dialogue site. "And both sides pay a price. The Palestinians are paying in civilian losses, and we're paying in world condemnation."

The march was proposed at an impromptu meeting of the Rafah emergency committee, consisting of various Palestinian political and militant factions, on Wednesday morning, according to Ghazi Hamad, a committee member who represents the militant Islamic Resistance Movement, known as Hamas. The stated goal was to break through the military cordon and deliver food, milk and water to Tel Sultan. But Hamad said the organizers understood from the start that the demonstrators would never make it to Tel Sultan. The real purpose was to draw media attention to the deteriorating situation there.

Hamad said he and other organizers insisted that no armed militants take part. "There were no fighters in the crowd," he said.

When the crowd started gathering at Awdah Square around noon, some of the earliest arrivals were children, who appeared to range in age from 10 to 15, carrying banners from the various factions. They were part of the vanguard at the front of the procession, which proceeded down Bahar, the main road from central Rafah to Tel Sultan.

Israeli army officials say they began to hear reports of the march at around this time from their intelligence sources in Rafah. They say an Israeli liaison officer, Col. Yoav Mordechai, called Palestinian leaders to plead with them to call off the rally. When the march began, Israelis contend that their intelligence sources and observation posts spotted armed men in the crowd.

By the time the front of the march reached the bend in the road, their ranks had swelled to nearly 2,000. Those in front say they could make out an Israeli tank in the distance. Many in the crowd hesitated, but about 50 to 100 -- mostly young men and boys -- slowly moved forward beyond the point where no one had gone in three days.

What they could not see, according to the Israeli military commander in charge of Gaza, Brig. Gen. Shmuel Zakai, was a group of soldiers stationed in a concealed observation and sniper post near the street that was in danger of being cut off from the tanks and surrounded.

To scare off the protesters, Zakai told journalists in a briefing Friday, the Israelis launched a series of warning shots -- first a missile from a helicopter gunship, then flares from the same chopper, then machine gun fire into a wall. None of these deterred the marchers, he said.

As a further warning, Zakai said, the commander of the tank brigade gave the order to the tank to open fire on an abandoned building near the marchers. In accord with standard practice, the tank fired four shells. The tank commander could not see the advancing demonstrators from his vantage point inside the Merkava tank.

The Israelis say they are still not certain why the shells hit the crowd. Col. Pinchas Zoaretz, the senior commander in Rafah, who has reviewed the army's video footage of the incident, said in a telephone interview that he believed one or more of the shells might have ricocheted off the abandoned building.

Soon after the incident, Zoaretz said, he talked to the commander of the tank battalion, a lieutenant colonel, who was devastated by what had happened. "He felt sorry that because of his decision innocent people were killed," recalled Zoaretz, who said he told the commander, "This is a war. Don't agonize over it. It was not done with evil intent."

In the mayhem that ensued, each side quickly sought to define the event. Palestinians at first put the death toll at 22 -- an exaggeration that officials of Najar Hospital later attributed to the fact that before the bodies arrived at the hospital's already overcrowded morgue, workers hauled out corpses from previous incidents, leading to a double count of victims.

Palestinian officials charged the Israelis with deliberately using lethal force. Hamad said soldiers had kept shelling the demonstrators even after the first shell hit. "We never expected that they would do something like this," he said of the Israelis.

The army immediately expressed deep regret for the killings. But Zoaretz said the march was another example of how militants exploit women and children for their cause. While four of the eight people killed were children younger than 15, he said, one of the others was armed and two or three had ties to militant groups.

Nonetheless, the Palestinian account attracted widespread international sympathy. Even the United States, Israel's closest ally, felt compelled to abstain in a 14-to-0 vote in the U.N. Security Council condemning the incident.

Palestinians won less sympathy from Israeli public opinion. Despite an initial wave of dismay from some lawmakers, much of the public seemed unmoved. Even on the streets and in the cafes of Jerusalem's German Colony, a center of pro-peace sentiment, few expressed remorse.

The fact that U.S. forces killed approximately 40 Iraqi civilians that same day in an attack that witnesses say was on a wedding party but that U.S. officials say was on insurgents helped compound the Israeli sense of self-justification. "Look at the Americans in Iraq," said military analyst Alpher. "In an empty desert you managed to hit 40 civilians."

Correspondent Robin Shulman contributed to this report.

A young Palestinian stands in front of a pool of raw sewage left in the street after local infrastructure was destroyed during Israel's incursion into Rafah last week.