A United Nations inquiry into human rights violations during the Gaza conflict has found that both Israelis and Palestinians committed war crimes and possibly crimes against humanity during the three week-long conflict that began last December. 

South African Justice Richard Goldstone said he and the three other members of his fact-finding commission came to their conclusions after reviewing more than 10,000 pages of documents, more than 1,000 photographs and videos, and interviewing nearly 200 people.

"We came to a conclusion on the basis of the facts we found that there was strong evidence to establish that there were numerous serious violations of international law - both humanitarian law and human rights law - were committed by Israel during its military operations in Gaza," he said. "The mission concluded that actions amounting to war crimes, and possibly in some respects, crimes against humanity, were committed by the Israel Defense Force."

He said those violations included the bombing of a mosque where several hundred people were worshipping and the shelling of an area next to a U.N.-run school.  Both incidents resulted in numerous civilian deaths and injuries.

Goldstone told reporters that Israel's use of white-phosphorus munitions, although legal, was concerning. He added that the destruction of Palestinian homes, factories, schools, hospitals and other infrastructure was unjustifiable.

"That sort of destruction cannot be justified by international law and particularly international humanitarian law at all," said Goldstone. "It really had nothing to do with purpose which Israel gave of the military operation - namely to stop the firing of rockets and mortars."

The Israeli government did not cooperate with the Goldstone commission, calling its mandate "one-sided" and "unbalanced." In a statement Tuesday, its foreign ministry rejected the report's findings, saying it had conducted its own investigations.

The Goldstone commission also accused Palestinian armed groups that fired rockets and mortars from the Hamas-controlled Gaza Strip into southern Israel of committing war crimes.

"There is no question that the firing of rockets and mortars was deliberate and calculated to cause loss of life and injury to civilians and damage to civilian structures," he said.  "The mission found that these actions also amount to serious war crimes, and also possibly crimes against humanity."

At least 1,300 Palestinians and 13 Israelis were killed in the three-week conflict.

Justice Goldstone said the commission, which began its work in May, carefully weighed what would constitute appropriate accountability.

He said the commission is recommending that the U.N. Security Council adopt a resolution requiring Israel and the authorities in the Gaza Strip to launch separate domestic investigations into their alleged violations.

He said both sides may be unwilling to do so, but they have the capacity to launch transparent investigations and follow through with prosecutions.

Goldstone said they recommended that both sides be given six months to conduct the investigations and report back to the Security Council on their progress. If no progress is made, then the Security Council should refer the matter to the International Criminal Court at The Hague.