Israel's top military prosecutor is investigating an army commander accused of repeatedly firing at the lifeless body of a young Palestinian girl.
Doctors said Iman al-Hams was hit by about 20 bullets
Soldiers said they pleaded with the officer to stop as he sprayed Iman al-Hams, 13, with automatic gunfire.
She had been shot by Israeli soldiers after straying into a restricted area near Gaza's border with Egypt.
Hundreds of Palestinian children have been killed by Israeli troops during the Palestinian uprising or intifada.
It is unusual for the army to launch an investigation into the circumstances of such incidents.
But the death of Iman al-Hams is different because soldiers have complained publicly about the behaviour of their commander - who has not been named.
Without revealing their identities, soldiers from the Givati brigade platoon told Israeli television how Iman al-Hams had been shot on 5 October in the Tel Sultan neighbourhood of Rafah.
"We saw her from a distance of 70 metres. She was fired at ... from the outpost. She fled and was wounded," a soldier said.
While Iman was lying, wounded or dead, about 70m from the Israeli guard post, the platoon commander approached her and fired two bullets from close range at her head, the soldiers said.
He then went back a second time, put his weapon on the automatic setting and - ignoring their objections on the walkie-talkie - emptied his entire magazine into her body.
"We couldn't believe what he had done. Our hearts ached for her. Just a 13-year-old girl," one soldier said.
"How do you spray a girl from
close range? He was hot for a long time to take out terrorists and shot the girl to relieve pressure," the soldier added.
Heavily-armed Israeli outposts line Gaza's border with Egypt
It is not clear from reports whether the investigation will focus on the initial shooting of Iman al-Hams or the officer's subsequent behaviour.
"Confirming the kill" - as Israeli troops call shooting combatants at close range to make sure they are dead - goes against Israeli military regulations governing the rules of engagement, Haaretz newspaper reported.
Palestinian witnesses say it was more than an hour before the Israeli troops would let medics get to the body in an ambulance.
Initially the Israeli army had said Iman al-Hams was shot because she was suspected of carrying a bomb to the army outpost.
It was reported that the Israeli troops had initially thought her satchel contained explosives - although it was found only to contain school books.
Chief of Staff Lieutenant General Moshe Ayalon defended his troops on Sunday, telling the Israeli cabinet that Iman al-Hams had been sent towards the outpost to draw out the soldiers so that Palestinian snipers could fire at them.
Her brother Ihab al-Hams angrily brushed off news of the investigation.
"Will this bring her back to life? Will this bring her back home? Will this heal our wound?" he told reporters.
"They are murderers and they killed her in cold blood."
Israel's army has occupied the Gaza Strip since 1967. Prime Minister Ariel Sharon wants to pull troops and settlers out of the territory, while retaining full control of its borders, coastline and airspace.