A majority of Palestinians killed in dozens of Israeli attacks on Gaza homes in the 2014 war with Hamas were women, minors or the elderly, and some of the strikes violated the rules of war, an Israeli rights group said Wednesday.

The B'Tselem group called strikes on homes "one of the appalling hallmarks of the fighting" and said they were approved at the top levels of Israeli power.

"There is no question in our minds that this is not the outcome of a low-level decision, but rather a matter of policy, a policy that in some cases has violated international humanitarian law," said the group's director, Hagai El-Ad.

The Israel Defense Forces said Wednesday it only attacked residential buildings that "became legitimate military targets." The army said it makes "extensive efforts to minimize harm to civilians."

Israel fought the war to halt rocket fire from Gaza.

During the fighting, Israel launched about 5,000 airstrikes and unleashed thousands of rounds of artillery at Gaza, while Gaza militants fired about 4,300 rockets and mortar rounds at Israel. More than 2,200 Palestinians were killed, according to U.N. figures. Sixty-seven soldiers and five civilians were killed on the Israeli side.

As part of the fighting, Israel attacked dozens of Gaza homes, claiming they were being used as military command centers or for storing weapons.

In most cases, the military refused to say exactly who or what was targeted.

B'Tselem looked at 70 strikes, each of which killed at least three people -- a portion of the overall total of attacks. More than 70 percent of 606 Palestinians killed in these 70 strikes were minors, women and older men, the group said.

Another Israeli group, NGO Monitor, said the count was skewed by underreporting deaths of combatants.

International law experts say even a high civilian death toll does not, on its own, constitute evidence of war crimes, and that each case has to be examined separately.

The Israeli military says all of the incidents cited in the B'Tselem report had been referred to investigators.