Arab leaders at a Cairo summit on Saturday condemned Israeli bombardment of Gaza as Europeans said civilians should be shielded, but with Israel and senior U.S. officials absent there was no agreement towards containing the violence.

Egypt, which called the meeting and hosted it, said it had hoped participants would call for peace and resume efforts to resolve the decades-long Palestinian quest for statehood.

At a peace summit in Egypt, UN chief Antonio Guterres urged a humanitarian ceasefire "to end this godawful nightmare."

The summit ended without a joint statement however, with Western officials demanding a clear condemnation of Hamas, and Arab attendees issuing their own statement criticising world leaders.

Inside Gaza, shellshocked residents said they were unsure where to go or how to protect their families.

"Even in my worst nightmares, I never thought this could be possible," said Rami Abu Wazna, staring at the destruction in central Gaza's Al-Zahra neighbourhood.

The scale of the bombing has left basic systems unable to function, with the UN reporting around 40 unidentified bodies were buried in a mass grave in Gaza City on Saturday because cold storage ran out before they could be identified.

Across the border in Israel's Kibbutz Beeri, where Hamas militants killed 10 percent of the population, preparations were underway for funerals on Sunday.

Romy Gold, 70, said residents were still struggling to comprehend the horror of their experience.

"Around us whole families were shot or butchered or burned alive," he told AFP.

Like many, he believes ground invasion of Gaza "cannot come fast enough. Something needs to be done."

"We need some kind of assurance that it will not happen again," he said.