The UN has held an unprecedented public hearing in Gaza to broadcast live witness accounts from Palestinians who described seeing their relatives killed and injured during Israel's January war.

One after another, they detailed Israeli rocket strikes and artillery shelling near a mosque, a UN school and on several homes across Gaza during the three-week war. The two-day hearing is part of an inquiry by the UN human rights council into the war led by the respected South African judge, Richard Goldstone.

Israel has refused entry for the inquiry team, accusing the UN council of an anti-Israel bias even though Goldstone himself is Jewish. But another round of hearings will be held in Geneva next week, for which some Israeli witnesses are expected to be flown in. They may include residents of Sderot, near Gaza, which has suffered repeated Palestinian rocket attacks.

"The purpose of the public hearings in Gaza and Geneva is to show the faces and broadcast the voices of victims – all of the victims," Goldstone said last week. He had sat on South Africa's constitutional court after the fall of apartheid and was a chief prosecutor on the UN criminal tribunals for the former Yugoslavia and Rwanda.

Yesterday's public hearing was the first in a UN fact-finding mission, though there is little chance it will lead to prosecutions. Up to 1,400 Palestinians and 13 Israelis were killed during the war.

Mousa Silawi, 91, described an explosion at the entrance to a mosque in the Jabaliya refugee camp late on 3 January, which killed 17 people, including three of his sons and two grandchildren.

"After evening prayer a huge shell hit the mosque," he said. "It was absolutely incredible. We starting screaming and calling for God." Silawi, who is blind, was led away to safety and was then told that his sons had died. "Where is law? Where is justice? I have lived 91 years. I have seen everything, but nothing of this sort. It was such a catastrophe," he said. His son, Moteeh, the mosque's sheikh, said there had been no warning before the missile struck. "People came to the mosque for safety and we saw bloodshed," he said. "I was leading my father out when my own foot stepped on the head of a small child," he said. "I saw people carrying decapitated heads and parts of bodies. I cannot describe what I saw … What crime did the children commit?"

In another case Ziad al-Deeb, a university student, described how an Israeli shell struck in the courtyard of his family home in Jabaliya on 6 January. The blast killed 11 of his relatives and sliced off both his legs. First he heard an explosion just outside the wall of the house and then moments later a second shell landed in their yard.

"In a single instant we had all of our joys replaced with blood," he said. "There was a severe whistling in my ears and a pillar of smoke and dust and that obliterated what happened. When I looked up I found I had lost both my legs. I was sprawled over the body of my own brother. I looked for my father and others, and I found them motionless. Most of them were dead."

He lost his father, grandfather, two brothers and a sister in the blast, which was one of several mortar shells that fell in quick succession that afternoon near a UN prep school being used as a shelter for those fleeing the fighting. Between 30 and 40 Palestinians were killed near the school. An earlier UN inquiry has already found Israel responsible for the shelling.

After hearing his evidence, Goldstone said: "We extend our deep condolences to you and your family for your terrible loss and it makes your coming here all the more painful for you."

Yesterday's hearing was held at a UN office in Gaza City and then broadcast live to a hall at a nearby cultural centre, deserted save for a handful of journalists. However, the hearing was broadcast on some television stations, including one al-Jazeera channel. The UN inquiry team will issue a final report in August.