Raed al-Athamna stands by the ruins of his destroyed house on Jan. 27 in Abed Rabbo, a village on the outskirts of the city of Gaza. (Mohammed Salem/Reuters)

The Israeli military is questioning the reliability of a Human Rights Watch report that accuses Israeli soldiers of killing Palestinian civilians who held up white flags during last winter's Gaza offensive.

“The report is based on the testimonies of a few Palestinian civilians whose credibility has not been proven,” the Israeli Defence Force said in a statement.

The IDF stressed that soldiers have an obligation to avoid harming anyone waving a white flag but that Hamas militants at times used civilians with white flags for protection during the conflict.

"Any person who displays a white flag in this way acts illegally, does not enjoy protection from retaliatory action, and endangers nearby civilian populations," the military said.

The report alleges that Israeli soldiers killed 11 unarmed Palestinian civilians waving white flags, including five women and four children, during an offensive in December 2008 and January 2009. It says the killings occurred when the civilians were “in plain view and posed no apparent security threat."

“All available evidence indicates that Israeli forces had control of the areas in question, no fighting was taking place there at the time, and Palestinian fighters were not hiding among the civilians who were shot,” the report said.

The group said it conducted “extensive investigations” into each of the incidents, interviewed multiple witnesses and at least three people for each attack.

"In each of these incidents, the evidence strongly indicates that, at the least, Israeli soldiers failed to take feasible precautions to distinguish between civilians and combatants before carrying out the attack. At worst, the soldiers deliberately fired on persons known to be civilians.”

Shortly after the new report was released, Israeli government spokesman Mark Regev questioned the organization's objectivity.

Regev did not directly comment on the Gaza allegations, instead referring to a recent flap over Human Rights Watch's fundraising activities in Saudi Arabia. The group came under fire for reportedly highlighting its criticism of Israel at a meeting attended by several Saudi officials.

This, Regev said, "raises important questions about the organization's impartiality, professionalism and credibility."

With files from The Associated Press