JERUSALEM — Amnesty International has accused armed Palestinian groups, including the military wing of Hamas, of displaying “a flagrant disregard for the lives of civilians” during the 50-day war in Gaza last summer. In a report published early Thursday it said there was evidence that several deadly Palestinian rocket and mortar attacks amounted to war crimes.

The 63-page report came a week before a formal Palestinian accession to the International Criminal Court in The Hague, due to take effect on April 1. Palestinian officials have said that they plan to file a complaint against Israel for alleged war crimes during the last Gaza war and for settlement activity.

An Amnesty International report published in November accused Israel of war crimes in its campaign against Hamas in the Gaza Strip last summer, saying its military showed “callous indifference” to civilians in airstrikes on homes, some of which devastated entire families.

But once the Palestinians are members of the court they could themselves become the subject of war crimes investigations.