Israeli forces and Palestinian militant groups carried out attacks during May's Gaza conflict that apparently amount to war crimes, Human Rights Watch says.
An investigation by the campaign group into what it says were three Israeli strikes that killed 62 civilians found no evidence of military targets nearby.
The Israeli military says it only struck military targets in Gaza.
The report also says the 4,300 rockets militants fired at Israel constituted indiscriminate attacks on civilians.
The UN said at least 129 of those killed in Gaza were civilians.
Human Rights Watch's investigation focused on what it says were three Israeli attacks that resulted in high numbers of civilian casualties:.
The report says "there were no evident military targets in the vicinity" of the three sites, and that "an attack that is not directed at a specific military objective is unlawful".
An Israeli military spokesperson was quoted by the report as saying that it "strikes military targets exclusively" and "makes concerted efforts to reduce harm to uninvolved individuals".
On Tuesday, the Israeli military told AFP news agency that Human Rights Watch "was choosing to recycle previously refuted allegations instead of condemning violations of international law by Hamas and other terrorist organisations, who are carrying out military operations from areas containing homes, mosques, schools and hospitals".
Human Rights Watch says Palestinian militants violated the prohibition against deliberate or indiscriminate attacks against civilians by firing unguided rockets towards Israeli cities and towns.