JERUSALEM — In the two months since Israel ended its military assault on Gaza, Palestinians and international rights groups have accused it of excessive force and wanton killing in that operation, but the Israeli military has said it followed high ethical standards and took great care to avoid civilian casualties.

Now testimony is emerging from within the ranks of soldiers and officers alleging a permissive attitude toward the killing of civilians and reckless destruction of property that is sure to inflame the domestic and international debate about the army’s conduct in Gaza. On Thursday, the military’s chief advocate general ordered an investigation into a soldier’s account of a sniper killing a woman and her two children who walked too close to a designated no-go area by mistake, and another account of a sharpshooter who killed an elderly woman who came within 100 yards of a commandeered house.

When asked why that elderly woman was killed, a squad commander was quoted as saying: “What’s great about Gaza — you see a person on a path, he doesn’t have to be armed, you can simply shoot him. In our case it was an old woman on whom I did not see any weapon when I looked. The order was to take down the person, this woman, the minute you see her. There are always warnings, there is always the saying, ‘Maybe he’s a terrorist.’ What I felt was, there was a lot of thirst for blood.”

The testimonies by soldiers, leaked to the newspapers Maariv and Haaretz, appeared in a journal published by a military preparatory course at the Oranim Academic College in the northern town of Tivon. The newspapers promised to release more such anecdotal accounts on Friday, without saying how many.

The academy’s director, Dany Zamir, told Israel Radio, “Those were very harsh testimonies about unjustified shooting of civilians and destruction of property that conveyed an atmosphere in which one feels entitled to use unrestricted force against Palestinians.”

The revelations caused an immediate uproar here, with some soldiers and reservists saying they did not recognize the stories being told as accurate.

Defense Minister Ehud Barak told Israel Radio that he believed such incidents to be exceptions, adding, “The Israeli Army is the most moral in the world, and I know what I’m talking about because I know what took place in the former Yugoslavia, in Iraq.”

It was clear that Mr. Zamir felt that his concerns, which he had raised earlier in a letter to the military chief of staff, Lt. Gen. Gabi Ashkenazi, had not been taken seriously and that was why he published the testimonies.

Since the war ended, others have raised similar questions, generating a heated debate within military circles.

“According to the code, a soldier has to do his utmost to avoid civilian casualties and that involves taking some risk,” said Moshe Halbertal, a Jewish philosophy professor at Hebrew University who, along with three others, rewrote the military ethics code eight years ago. “That is the question we have to struggle with. From the testimonies of these soldiers, it sounds like they didn’t practice this norm.”

Amir Marmor, a 33-year-old history graduate student in Jerusalem and a military reservist, said in an interview with The New York Times that he was stunned to discover the way civilian casualties were discussed in training discussions before his tank unit entered Gaza in January. "Shoot and don’t worry about the consequences,” was the message from the top commanders, he said. Speaking of a lieutenant colonel who briefed the troops, Mr. Marmor said, “His whole demeanor was extremely gung ho. This is very, very different from my usual experience. I have been doing reserve duty for 12 years, and it was always an issue how to avoid causing civilian injuries. He said in this operation we are not taking any chances. Morality aside, we have to do our job. We will cry about it later.”

Some 1,300 people were killed in the Gaza war, but how many of them were combatants remains a matter of controversy. Israel lost about 10 soldiers in Gaza, some because of fire by its own forces.

The Gaza-based Palestinian Center for Human Rights, which has documented the Gaza deaths, says that about two-thirds of the 1,300 were civilians, among them 121 women and 288 children, which it defines as anyone 18 and younger.

But the Institute for Counter-Terrorism in Israel said Thursday that it had analyzed the Palestinian center’s names and found that some that it listed as civilians were identified as combatants on Hamas-related Web sites. Some listed as children were 17-year-olds with guns, it said, adding that more than 500 of those described by the center as civilians it considered “unknowns” because most were men of combat age whose activities could not be easily traced.

It argued that the proportion of women and children among the dead was relatively low, showing that Israel had not killed in an indiscriminate fashion.

Gur Rosenblat, a company commander during the Gaza operation, said in an interview: “To say that people were killed without justification — the opposite was true. We put soldiers at risk to prevent harming their civilians.”

Israeli experts noted that Palestinian women had served as suicide bombers in the past so that soldiers in Gaza did not always know when a woman was approaching whether she was a threat.

One of the soldiers’ testimonies involved the killing of a family. The soldier said: “We had taken over the house, and the family was released and told to go right. A mother and two children got confused and went left. The sniper on the roof wasn’t told that this was O.K. and that he shouldn’t shoot. You can say he just did what he was told.”

Much of what happened in Gaza, some military experts said, was in reaction to the way events unfolded in the second Lebanon war in 2006 when Hezbollah caused many Israeli casualties.

In that war, when Israeli soldiers took over a house, they sometimes found themselves shot at from a house next door. The result was that in Gaza, many houses next to those commandeered by troops were destroyed to avoid that risk.

Still, Israeli ethicists say they are troubled by what they have heard.

“Unfortunately, I think that selective use of killing civilians has been very much on the agenda for fighting terror,” said Yaron Ezrahi, a political scientist at Hebrew University who has been lecturing at defense colleges. “The army believes that a weak spot of Israeli deterrence is its strong commitment not to kill civilians, and there has grown the sense that it might have to temporarily overcome that weakness in order to restore deterrence.”