An Israeli human rights group says many more Palestinian civilians were killed in the Israeli military's campaign this year in Gaza than the army admits.
B'Tselem said detailed research showed that out of 1,400 Palestinian deaths, 773 were civilians - many of them children.
The research contradicts an Israeli army report stating that fewer than 300 civilians died in the fighting earlier this year, the BBC reports.
Israel launched the assault to halt rocket attacks from Hamas-run Gaza.
Amnesty International has already accused Israel of having committed war crimes during its offensive.
B'Tselem said the findings had been compiled during months of research, including visits to the families of those killed.
The group said the results should compel the Israeli government to launch an independent investigation into its three-week offensive.
Earlier this year the Israeli army said that 1,166 Gazans were killed in the conflict.
The army said this figure included 709 militants from Hamas and other groups, and 295 non-combatants.
According to B'Tselem, 1,387 Palestinians were killed. It says that figure includes 773 civilians, 330 combatants, 248 Palestinian police officers - whom Israel counts in its figure of militants - and 36 people whose role was unclear.