UN envoy Archbishop Desmond Tutu, concluding a fact-finding mission to the Hamas-ruled Gaza Strip on Thursday, condemned as a "massacre" the killing of 18 members of a Palestinian family by Israeli shelling in 2006.
At a news conference, Tutu said Israel's contention that a technical fault caused the shells to hit two homes in the Gaza town of Beit Hanoun, a border area where militants fire rockets at southern Israel, "fell short of accountability".
The Nobel Peace Prize laureate planned to present a report about the incident to the UN Human Rights Council in Geneva at a session in September.
"We are at the stage of shock... by what we subsequently heard from the survivors of the November (2006) Beit Hanoun massacre," Tutu said.
The South African cleric said a main aim of the visit was to "make recommendations to protect Palestinian civilians from further Israeli assaults".
He also urged militants to stop launching rockets at Israel.
"We told Mr (Ismail) Haniyeh that firing rockets was a gross violation of human rights," Tutu said, referring to the Gaza-based Hamas leader.
Tutu called on Israel to end a blockade of the Gaza Strip, saying the international community's "silence and complicity, especially on the situation in Gaza, shame us all".