Israel has cast the deaths of civilians in the Gaza Strip as a regrettable but unavoidable part of modern conflict, pointing to the heavy human toll from military campaigns the United States itself once waged in Iraq and Syria.

But a review of past conflicts and interviews with casualty and weapons experts suggest that Israel’s assault has been different.

While wartime death tolls will never be exact, experts say that even a conservative reading of the casualty figures reported from Gaza shows that the pace of death during Israel’s campaign has few precedents in this century.

People have been killed in Gaza more quickly, they say, than in even the deadliest moments of U.S.-led attacks in Iraq, Syria and Afghanistan, which were themselves widely criticized by human rights groups.

Precise comparisons of war dead are impossible, but conflict-casualty experts have been taken aback at reports of how many people have been killed in Gaza — most of them women and children — and how rapidly.

It is not just the scale of the strikes — Israel said it had engaged more than 15,000 targets before reaching a brief cease-fire on Friday. It is also the nature of the weaponry.

Israel’s liberal use of very large weapons in dense urban areas, including U.S.made 2,000-pound bombs that can flatten apartment towers, is surprising, some experts say.

“It’s beyond anything that I’ve seen in my career,” said Marc Garlasco, a military adviser for the Dutch organization PAX and a former senior intelligence analyst at the Pentagon. To find a historical comparison for so many large

bombs in such a small area, he said, we may “have to go back to Vietnam, or the Second World War.”

In fighting during this century, by contrast, U.S. military officials often believed that the most common American aerial bomb — a 500-pound weapon — was far too large for most targets when battling the Islamic State in urban areas like Mosul, Iraq, and Raqqa, Syria.

The Israeli military points out that Gaza presents a battlefield like few others. It is small and dense, with civilians living next to, and even on top of, Hamas combatants who rely on tunnel networks to shield themselves and their weapons, putting residents directly in the line of fire, the military says.

Given these underground networks — which the military says enabled Hamas to wage its deadly attacks on Oct. 7 — Israeli forces say they have used the “smallest available ordnance” to achieve their strategic objectives to cause the “minimal adverse effect on civilians.”

Civilian casualties are notoriously hard to calculate, and officials in the Hamas-run Gaza Strip do not separate the deaths of civilians and combatants.

Researchers point instead to the roughly 10,000 women and children reported killed in Gaza as an approximate — though conservative — measure of civilian deaths in the territory. International officials and experts familiar with the way figures are compiled by health officials in Gaza say the overall numbers are generally reliable.

The Israeli military acknowledged that children, women and older people have been killed in Gaza, but said the death toll reported in Gaza could not be trusted because the territory is run by Hamas. The military did not provide a count of its own but said that civilians were “not the target” of its campaign.

“We do a lot in order to prevent and, where possible, minimize the killing or wounding of civilians,” said Lt. Col. Jonathan Conricus, an Israeli military spokesman. “We focus on Hamas.”

Still, researchers say the pace of deaths reported in Gaza during the Israeli bombardment has been exceptionally high.

More women and children have been reported killed in Gaza in less than two months than the roughly 7,700 civilians documented as killed by U.S. forces and their international allies in the entire first year of the invasion of Iraq in 2003, according to estimates from Iraq Body Count, an independent British research group.

And the number of women and children reported killed in Gaza since the Israeli campaign began last month has already started to approach the roughly 12,400 civilians documented to have been killed by the United States and its allies in Afghanistan during nearly 20 years of war, according to Neta C. Crawford, a University of Oxford professor who is co-director of the Costs of War Project at Brown University in Rhode Island.

These comparisons are based on the thousands of deaths directly attributed to U.S. coalition forces over decades in Iraq, Syria and Afghanistan. Far more people — hundreds of thousands in total — are estimated to have been killed in these conflicts by other groups, including the Syrian government and its allies, local militias, the Islamic State and the Iraqi security forces.

But while the overall death tolls in those wars were larger, the number of people killed in Gaza “in a very short period of time is higher than in other conflicts,” said Professor Crawford, who has extensively researched modern wars.

In the nine-month battle of Mosul, which Israeli officials have cited as a comparison, an estimated total of 9,000 to 11,000 civilians were killed by all sides in the conflict, including many thousands killed by the Islamic State, The Associated Press found.

A similar number of women and children have been reported killed in Gaza in less than two months.

The bombs that have been used in Gaza are larger than those the United States used when it was fighting ISIS in cities like Mosul and Raqqa, and are more consistent with striking at underground infrastructure like tunnels, said Brian Castner, a weapons investigator for Amnesty International and a former explosive ordnance disposal officer in the U.S. Air Force.

More than twice as many women and children have already been reported killed in Gaza than have been confirmed killed in Ukraine, according to United Nations figures, after almost two years of Russian attacks. (The United Nations believes the true toll in Ukraine is considerably higher, however, and Ukrainian officials have estimated that more than 20,000 civilians died in the port city of Mariupol.)

Not only is Gaza tiny when compared with conflict zones like Ukraine, Afghanistan or Iraq, but the territory’s borders have been closed by Israel and Egypt, giving civilians few, if any, safe places to flee.

More than 60,000 buildings have been damaged or destroyed in the Gaza Strip, satellite analysis indicates, including about half of the buildings in northern Gaza. “They are using extremely large weapons in extremely densely populated areas,” Mr. Castner said of Israeli forces. “It is the worst possible combination of factors.”

Israeli officials say their campaign has been focused on degrading Gazan military infrastructure that is often built near homes and civilian institutions — or buried underneath them.

“To get to that target,” Colonel Conricus said, the military has to use “larger bombs with a higher yield.”

When an Israeli government spokesman, Mark Regev, was asked in an Oct. 24 interview with PBS about the pace of the strikes, he said Israel was aiming for a shorter campaign than the United States waged in Iraq and Syria.

“Hopefully, we get it done quicker,” Mr. Regev said. “That’s one of our goals. But it could take longer than many Israelis would hope, because Hamas has been in power for 16 years.”

Israel has directed Gaza residents to evacuate areas where the bombing campaign is especially concentrated, but it has struck other areas as well.

More broadly, Israeli officials say this is a campaign on its own borders to wipe out Hamas, a group dedicated to Israel’s destruction. “The war here is for our existence,” one Israeli war cabinet minister, Benny Gantz, told reporters on Nov. 8.

After initially questioning the death toll in Gaza, the Biden administration now concedes that the true figures for civilian casualties may be even worse.

Barbara Leaf, the assistant secretary of state for Near Eastern affairs, told a House committee this month that American officials thought the civilian casualties were “very high, frankly, and it could be that they’re even higher than are being cited.”

International experts who have worked with the Gaza Health Ministry during this and other wars say it gathers death figures from hospitals and morgues across the enclave, which tally the dead and report the names, ID numbers and other details of people killed.

While the experts urged caution around public statements about the specific number of people killed in a particular strike — especially in the immediate aftermath of a blast — they said the aggregate death tolls reported by the Gaza Health Ministry have typically proved to be accurate.

In the past few weeks, recording the dead in Gaza has become increasingly difficult in the chaos of the fighting, as hospitals have come under direct fire, much of the health system has ceased to function and other government officials, rather than the ministry, have begun updating the number of killed.

But even before those changes, the number of women and children reported dead already outpaced numbers in other conflicts.

Women and children account for nearly 70 percent of all deaths reported in Gaza even though most combatants are men — an “extraordinary statistic,” Rick Brennan, the regional emergency director for the World Health Organization’s Eastern Mediterranean office, said at an event this month.

Normally, one would expect the opposite, Mr. Brennan said. In past clashes between Israel and Hamas, for example, about 60 percent of the reported deaths in Gaza were men.

The Israeli military spokesman, Colonel Conricus, said the high percentage of women and children reported killed in Gaza is a reason to mistrust the figures.