An Associated Press investigation into Israeli airstrikes on Gaza homes during last summer’s war against Hamas concluded that 508 people, or over 60 percent of the casualties, were children, women and older men.

The report, which the Associated Press called “the most painstaking attempt to date to try to determine who was killed in strikes on homes,” was compiled by investigating 247 Israeli airstrikes and interviewing witnesses.

Israel launched air strikes after an intensification of rocket fire attacks launched from Gaza onto southern Israeli towns.

Israeli officials have accused Hamas and other groups of launching attacks from population-dense areas. According to Israel, Palestinian groups used houses to hide weapons, fighters and command centers. Israeli officials said they used safeguards against hitting civilians, including calling off strikes at the last minute when civilians appeared and delivering warnings so civilians could evacuate.

The AP report concluded that 96 of those killed in airstrikes, or 11 percent of the total casualties, were “confirmed or suspected militants.” The Associated Press acknowledged that its numbers could be wrong since Hamas has not released a detailed casualty list.

The number of civilian deaths has been a central element of the heated discussion of the Gaza conflict. In August 2014, the United Nations reported that 70 percent of the war’s total Palestinian casualties were civilians. Israel refuted that report.