A "lasting cease-fire" between Israel and Palestine is needed, a UNICEF spokesperson urged on Friday, hours after the Gaza humanitarian pause ended, quickly followed by a new wave of deadly Israeli attacks.

"A lasting cease-fire must be implemented. The alternative is unthinkable for people who are, as a Palestinian said ... already living in a nightmare," James Elder said. "More attacks on Gaza will not lead to anything but carnage."

Saying that new bombardments began hitting Gaza "very intensely" seconds after the pause came to an end, he stressed: "Inaction (to get to a cease-fire) at its core is an approval of the killing of children."

Elder stressed that this is "our last chance before we need to explain" why a war on children could not be stopped.

"To accept the sacrifice of the children in Gaza is humanity giving up," he said. "This is our last chance before we delve into yet again, explaining why another entirely avoidable tragedy was not stopped whilst no one thought to stop what is a war on children."

At least 32 Palestinians were killed and numerous others injured as Israel resumed striking various areas in the Gaza Strip soon after the end of the multi-day pause, said the Health Ministry in Gaza.