An Israeli platoon commander is under investigation following accusations by his fellow soldiers who claim he repeatedly shot a 13-year-old Palestinian girl after she had already been shot.

The Israeli army said they initially thought the girl was a bomb-carrying militant entering the restricted area of Rafah, a Gaza Strip refugee camp.

Soldiers said the girl was shot from more than 60 metres away.

A poster with a picture of the 13-year-old.

But some of the troops complained to Israeli media that the commander then approached the girl and repeatedly shot her as they pleaded with him to stop.

They said the platoon commander fired two bullets from close range to confirm that she was dead. He then allegedly went back a second time and sprayed her with automatic-weapon fire.

Soldiers told the Israeli newspaper Yediot that they shouted to the commander over the two-way radio: "Don't shoot, she's a little girl."

"We saw her from a distance of 70 metres. She was fired at ... from the outpost. She fled and was wounded. I understood that she was dead. The platoon commander neared her, shot two bullets at her, returned toward the force, turned back to her, put the weapon on automatic and emptied his entire clip," one soldier said.

A Palestinian doctor said the girl was hit by at least 15 bullets in her head, chest and legs.

Israel's top military prosecutor has opened an inquiry into the shooting and the army has its own investigation underway.

Israel launched its biggest offensive into Gaza on Sept. 30 following the launch of rockets by Hamas militants. At least 92 Palestinians and three Israelis have been killed since then.