Israel launched its operation on December 27 after a ceasefire with Hamas ended a week earlier, stating its objective was to target the Palestinian faction's infrastructure and bring an end to the firing of homemade rockets into southern Israel.
Fewer states than expected supported the resolution, which passed by 33 votes to one, with 13 abstentions. The US, not a member of the council, took no part in the debate.
Israel dismissed it as one-sided and reflecting the "fairytale world" of the 47-member council.
The text of the document said the council "strongly condemns the ongoing Israeli military operations ... which have resulted in massive violations of human rights of the Palestinian people and systematic destruction of the Palestinian infrastructure".
The resolution was opposed by Canada while European countries, Japan and South Korea abstained.
The resolution was backed by, among others, Russia, China, Argentina and Brazil.
During a debate on the resolution, Pakistan, speaking for the Organisation of the Islamic Conference (OIC), denounced what it called Israel's "unrestrained use of force, killing of innocent civilians" and violation of UN havens.
At least 40 people died last Tuesday when the UN-run school they were sheltering in was hit by Israeli fire.
All European Union countries abstained and Canada voted against the resolution.
Rupert Colville, a spokesman for the UN High Commissioner for Human Rights, told Al Jazeera: "In the end they [the UN] passed the resolution, it was not unanimous. I would not say it was that heated, at the end of the day there were still differences of opinion.
|Israel dismissed the non-binding resolution as one-sided [AFP]
"Many states praised the Palestinian delegation for the flexibility they had shown in the negotiations, but they could not quite reach a consensus."
Speaking in the Gaza Strip, John Ging, head of the United Nations Relief and Works Agency (UNRWA) operations in Gaza, repeated his call for an immediate end to the fighting.
"I say now, to all politicians, here in Israel and internationally, you have an obligation to the ordinary people in the name of humanity and all that is civilised, we need to stop this now. Those who help will never be forgotten.
"Israel is responsible for its own actions and it is very clear to us that there are a lot of actions in this conflict that will need to be fully investigated independently and internationally.
"Those who have been killed and injured, those who are innocent, deserve accountability."
Peter Splinter, Amnesty International's representative at the United Nations in Geneva, backed the call for an investigation, saying "there must be a full accountability for war crimes".
"Evidence of war crimes is presenting itself each day," he told Al Jazeera.
Boutros Boutros-Ghali, a former UN secretary-general, added his perspective on the situation, saying the assault on Gaza "is a present the Israelis gave to the fundamentalists".
"It will reinforce extremists, fundamentalists, all over Arab countries and even inside Israel," he said.
Boutros-Ghali headed the UN from 1992 to 1997.