Earlier, UN High Commissioner for Human Rights Navi Pillay said an alleged failure of the Israeli military to help wounded civilians in Gaza - cited by the Red Cross - could constitute a war crime.
On Thursday, the International Committee of the Red Cross said its staff had found four weak and scared children beside their mothers' bodies in houses hit by shelling in the Zeitoun neighbourhood of Gaza City.
Ms Pillay told the BBC: "The incident the Red Cross describes is very troubling because it has all the elements of what constitutes a war crime.
"There is an obligation to protect the wounded, to treat the sick, to remove them to safety and here, according to the Red Cross, Israeli soldiers just stood by and did nothing for these four children and one adult who were too weak to move."
The UN human rights body has demanded that human rights monitors be deployed in Gaza, Israel and the West Bank so that any violations of international law can be documented independently.
Separately, the UN's head of humanitarian affairs, John Holmes, said it was "extremely disappointing" that so far the resolution had been ignored by both sides.
Asked whether Israel was living up to its human rights obligations, US Secretary of State Condoleezza Rice told the AFP news agency it was hard for Israel to safeguard civilians because Gaza was a very densely populated area.
Israel continued its bombardment on Friday, although it paused operations for three hours in the afternoon to allow supplies to be brought in for Gaza's residents.
Some 50,000 people demonstrated in Egypt against the Gaza conflict
However, Israeli army spokesman Capt Eli Isaacson told the BBC that during that period, two rockets had been fired from Gaza towards Israel and that Israeli forces had returned fire.
Witnesses told the AFP news agency that targets in Zeitoun and in Jabaliya and Beit Lahiya in the north had been shelled.
Israel said Hamas militants had fired more than 30 rockets at southern Israel on Friday.
Hamas said it had rejected the UN's call for an immediate ceasefire because it was not to the advantage of the Palestinian people.
Ayman Taha, a Hamas spokesman in Gaza, said: "Even though we are the main actors on the ground in Gaza, we were not consulted about this resolution and they have not taken into account our vision and the interests of our people."
Officials in Mr Ehud's office were quoted as saying "the Israeli military will continue to protect Israeli civilians and carry out its missions".
Fourteen out of 15 Security Council members backed a resolution on the Gaza crisis, with the US abstaining.
The motion called for an "immediate, durable and fully respected ceasefire" leading to the "full withdrawal" of Israeli forces from Gaza.
It also demanded "the unimpeded provision and distribution throughout Gaza of humanitarian assistance", measures to prevent arms smuggling to Palestinian militants and the opening of border crossings into Gaza.
Israeli officials visited Cairo on Thursday to hear details of a plan put forward by Egypt and France.
A Hamas delegation was also expected in the Egyptian capital at some stage for parallel "technical" talks, Egyptian diplomats said.
Israel wants to stop rocket attacks on southern Israel and to stop Hamas smuggling weapons into Gaza via Egypt, while Hamas says any ceasefire deal must include an end to Israel's blockade of Gaza.
This page is best viewed in an up-to-date web browser with style sheets (CSS) enabled. While you will be able to view the content of this page in your current browser, you will not be able to get the full visual experience. Please consider upgrading your browser software or enabling style sheets (CSS) if you are able to do so.