More than one-third of the Palestinian civilians killed during Israel's operation in the Gaza Strip last November were under the age of 18, the Israeli human rights group B'Tselem said in a report released this week.

The B’Tselem based its findings on Operation Pillar of Defense on statements issued by the Israel Defense Forces, the Shin Bet security service, and on an internal investigation.

The IDF killed 167 Palestinians during the operation, at least 87 of them non-combatants, according to the data presented in the B'Tselem report.

Thirty-one of these non-combatant civilians, or 35 percent, were minors. Of these minors, 20 were under the age of 12, according to B'Tselem.

The B’Tselem report also segments the number of Palestinians killed on each of the eight days of fighting: during each of the first four days, an average of four "non-participant" Palestinians were killed; over the next four days, the number in this category soared by more than four to an average of 17.5 per day. The report also notes that during the first days of the fighting, the number of Palestinian combatants who were killed was nearly twice the number of non-combatant fatalities. In the subsequent days of the operation, this proportion was reversed.

B'Tselem notes that under the rules of international law which apply to both the army and armed Palestinian organizations, it is completely prohibited to target civilians. The report explicitly states that Hamas and other militant organizations in the Gaza Strip have violated this prohibition by, inter alia, firing directly at Israeli civilians and locales, firing from within civilian Palestinian neighborhoods whilst endangering the inhabitants, and hiding inside civilian buildings.

The B'Tselem report indicates that the IDF also operated in violation of international law at times, in at least some of the cases in which "non-participant" Palestinians were killed.

Military Advocate for Operational Matters Lt. Col. Ronen Hirsch told B'Tselem in response to its inquiry that the IDF prosecutor’s office sees no criminal act or substantiated suspicion of a violation of the rules of war in four of the incidents in question, and therefore closed the cases.

The IDF spokesman said in response to the report that the army had opened its own investigation into the civilian deaths. “At the end of Operation Pillar of Defense the chief of staff appointed a general staff investigation committee headed by Maj. Gen. Noam Tibon to examine the incidents."

"At the same time, the military prosecutor began a procedure of examining violations of the law by IDF soldiers during the operation," added the spokesman. "The investigation, which has not yet been completed, includes the gathering of data concerning the incidents in which, ostensibly, civilians who were not involved in the hostilities where injured and also cases about which complaints were not filed.”