Striking testimony has emerged from Israeli soldiers involved in the Gaza war in which they describe shooting unarmed civilians, sometimes under orders from their officers.

One soldier described how an Israeli sniper shot dead a Palestinian mother and her two children, adding that fellow troops believed the lives of Palestinians were "very, very less important than the lives of our soldiers".

The testimony, published in the Israeli newspaper Ha'aretz today, gives a rare insight into how Israeli soldiers fought the war on the ground; reinforces Palestinian accounts of disproportionate Israeli force; and sharply contradicts the Israeli military's official version of events.

The accounts come from unnamed soldiers who were graduates of a pre-military course at Oranim Academic College in Tivon and who spoke in a session in mid-February. The transcript of the session was published this week and obtained by Ha'aretz.

In that transcript, one infantry squad leader said: "There was a house with a family inside … We put them in a room. Later we left the house and another platoon entered it, and a few days after that there was an order to release the family. They had set up positions upstairs. There was a sniper position on the roof.

"The platoon commander let the family go and told them to go to the right. One mother and her two children didn't understand and went to the left, but they forgot to tell the sharpshooter on the roof they had let them go and it was OK, and he should hold his fire and he ... he did what he was supposed to, like he was following his orders. The sharpshooter saw a woman and children approaching him, closer than the lines he was told no one should pass. He shot them straight away. In any case, what happened is that in the end he killed them."

The squad leader said he believed the sniper did not feel regret. "I don't think he felt too bad about it, because after all, as far as he was concerned, he did his job according to the orders he was given. And the atmosphere in general, from what I understood from most of my men who I talked to ... I don't know how to describe it ... The lives of Palestinians, let's say, is something very, very less important than the lives of our soldiers. So as far as they are concerned they can justify it that way."

A second squad leader, from the same brigade, described how a company commander ordered troops to shoot an elderly Palestinian woman who was walking on a road about 100 metres from a house the soldiers had taken over. He said he argued with his commander about the rules of engagement, particularly the way they shot without warning to clear houses.

Ha'aretz reported: "After the orders were changed, the squad leader's soldiers complained that 'We should kill everyone there [in the centre of Gaza]. Everyone there is a terrorist.'"

The squad leader said: "You do not get the impression from the officers that there is any logic to it, but they won't say anything. To write 'death to the Arabs' on the walls, to take family pictures and spit on them, just because you can. I think this is the main thing: to understand how much the IDF [Israel Defence Forces] has fallen in the realm of ethics, really. It's what I'll remember the most."

The head of the Oranim course was apparently "shocked" after hearing the soldiers' accounts of their fighting and reported his concerns to the army chief, Major General Gabi Ashkenazi. Ashkenazi's office asked for a transcript of the discussion, which was provided.

The Israeli military today first denied having "any previous knowledge or information about these incidents". Then in a later statement it admitted that the head of the course had sent a letter to the chief of staff's office "several weeks ago" describing the soldiers' accounts and that the military's chief education officer then met with the course head.

It said the military advocate general, Brigadier General Avichai Mendelblit, today instructed the military police to investigate the soldiers' accounts.