Israel has not co-operated with the investigation led by Richard Goldstone
A UN war crimes investigator has said testimonies about the recent conflict in Gaza have been "difficult to hear" as four days of public hearings ended.
Richard Goldstone said his four member team had been shaken by the extent of the destruction in Gaza.
Witnesses from Gaza, Israel and the West Bank gave testimony in public hearings in Gaza and Geneva.
Israel has refused to co-operate, accusing the UN Human Rights Council of bias against it.
The investigation is looking into whether Israel and Hamas committed war crimes during Israel's three-week operation in Gaza in December and January.
The Human Rights Council has been accused of singling out Israel unfairly, although Mr Goldstone, who is Jewish, is a respected South African war crimes prosecutor.
Israel did not provide visas for the investigators to visit the south of Israel, which has suffered years of Palestinian rocket fire, or the West Bank, and the team entered Gaza from Egypt.
In two days of hearings last weeks, Gaza residents described harrowing stories of bereavement and injury during the Israeli operation.
And on Monday and Tuesday, residents of southern Israel, weapons experts, Palestinian lawyers and the father of captured Israeli soldier Gilad Shalit gave testimony.
"The testimonies we have heard from victims and witnesses... have been very difficult to hear, but I believe it is important that we listen to these stories," Mr Goldstone told a news conference.
"Obviously on this mission, visiting Gaza was very important, not only to listen to people but to see the physical damage. That shook all of us, the extent of it," Goldstone said.
It is the first time a UN fact-finding mission has held such public hearings.
Mr Goldstone said written questions would now be submitted to Israel and Hamas and the team was aiming to present its report in September.
Several investigations into alleged violations of international law during Israel's 22-day operation in Gaza, which ended on 18 January, have now reported back.
DIFFERENT DEATH TOLLS
Palestinians killed during Israeli military offensive in Gaza, 27 Dec to 18 Jan - Palestinian claims followed by Israelis claims:
Total dead: 1,434 / 1,166
Non-combatants: 906 / 295-460
Children under 16: 288 / 89
Sources: Palestinian Centre for Human Rights and Israeli Defence Intelligence Research Dept
UN Secretary General Ban Ki-moon has requested more than $11m (£7m) compensation from Israel for damage to UN property in Gaza, after a limited UN inquiry accused Israel of targeting known civilian shelters and providing untrue statements to justify actions in which civilians were killed.
The report found Israel to blame in six out of nine incidents when death or injury were caused to people sheltering at UN property and UN buildings were damaged.
The Israeli military has concluded in an internal investigation that its troops fought lawfully, although errors did take place, such as the deaths of 21 people in a wrongly targeted house.
International human rights group Amnesty International accused both sides of committing war crimes in a detailed report on the conflict last week.
Palestinian rights groups say more than 1,400 Palestinians were killed during the January conflict. Israel puts the figure at 1,166.
Israeli and Palestinian estimates also differ on the numbers of civilian casualties.
According to the United Nations, the Israeli military campaign left more than 50,000 homes, 800 industrial properties and 200 schools damaged or destroyed, as well as 39 mosques and two churches.
Ten Israeli soldiers were killed, including four by friendly fire, and three Israel civilians died in rocket attacks by Palestinian militants.