Israel has angrily rejected what it called a "one-sided" resolution by the UN human rights council today that backed a highly critical report on the Gaza war and opened the way to possible international war crimes investigations.

The council voted to endorse the report by a South African judge, Richard Goldstone, which accused both Israel and Hamas of committing war crimes and possible crimes against humanity during the three-week war in Gaza in January. Goldstone, whose work was hailed by leading international human rights groups, found there may be individual criminal responsibility over the killing of civilians.

The report will go to the UN general assembly and could lead to a rare international criminal court investigation if Israel and Hamas fail to mount their own credible independent inquiries into the war crimes allegations within six months.

Today's vote carries major implications for the Middle East conflict. It is the first time such serious investigations have been contemplated at such a high level. It may encourage reconciliation between the rival Palestinian factions, but it is also likely to complicate US efforts to restart Israeli-Palestinian peace talks. And in the end it may result in a US veto at the UN security council to protect Israel from scrutiny.

"Israel rejects the one-sided resolution adopted in Geneva by the UN human rights council and calls upon all responsible states to reject it as well," the Israeli foreign ministry said. The resolution "provides encouragement for terrorist organisations worldwide and undermines global peace". Israel has criticised the council in the past for an anti-Israel bias.

In Ramallah, a spokesman for the Palestinian president, Mahmoud Abbas, welcomed the result but said he wanted to see action. "What is important now is to translate words into deeds in order to protect our people in the future from any new aggression," said Nabil Abu Rdeneh.

Hamas for its part welcomed the resolution as "the beginning of the prosecution of the leaders of the occupation," even though it too risks international investigations.

The resolution not only dealt with the Goldstone report but condemned Israel's policies in east Jerusalem, particularly over access to Muslim holy sites, demolitions of Palestinian homes and excavation work near the Haram al-Sharif, also known as the Temple Mount.

It was passed with 25 votes in favour, six against and 11 abstentions. The US voted against the resolution, while Britain and France did not take part after failing to secure a delay. Neither Israel nor the Palestinians sit on the 47-member council, which is dominated by countries in the developing world, but both worked hard to influence the outcome of the vote.

Intense US pressure initially led Abbas to drop his efforts to secure a vote endorsing the Goldstone report. Abbas had wanted to put the vote off for six months, but that was greeted with such an outcry among Palestinians who demanded accountability for the hundreds of civilians killed in Gaza that he quickly backtracked and called for this special council session.

Goldstone had recommended that the human rights council pass his report to the UN security council, the UN general assembly and the international criminal court. He proposed that both Israel and Hamas should be given six months to conduct their own "appropriate investigations that are independent and in conformity with international standards". If either side failed to investigate properly, then he said the security council should pass the case on to the prosecutor of the international criminal court.

Hamas looks unlikely to investigate its actions during the war and Israel's prime minister, Binyamin Netanyahu, has already insisted he will not allow any Israelis to face war crimes trials. Around 1,400 Palestinians and 13 Israelis died in the three-week war.

The US diplomat at the council in Geneva, Douglas Griffiths, criticised the Goldstone report for an "unbalanced focus on Israel, the overly broad scope of its recommendations and its sweeping conclusions in law". However, he also said Washington had wanted more time before the vote to allow the two sides to conduct their own investigations into war crimes allegations. That suggests the US may yet put pressure on Israel to hold a credible inquiry. Western countries may be concerned that they too could face the threat of similar investigations in future over their conduct in wars in Iraq and Afghanistan.

The UN high commissioner for human rights, Navi Pillay, called on both sides to hold "impartial, independent, prompt and effective investigations".

Gordon Brown reportedly had a heated telephone call on Wednesday with Netanyahu, who pressed him to vote against the resolution. Brown spoke again with Netanyahu this morning, hours before the vote, and Britain then decided not to take part at all. A Downing Street spokesman said: "We did not participate in the vote. We were involved in discussions with Israel and the Palestinians about potentially substantive improvements in the situation on the ground and therefore asked for a delay to the vote."

How they voted

In favour (25): Argentina, Bahrain, Bangladesh, Bolivia, Brazil, Chile, China, Cuba, Djbouti, Egypt, Ghana, India, Indonesia, Jordan, Mauritius, Nicaragua, Nigeria, Pakistan, Philippines, Qatar, Russia, Saudi Arabia, Senegal, South Africa, Zambia.

Against (6): US, Italy, Holland, Hungary, Slovakia, Ukraine.

Absentions (11): Belgium, Bosnia, Burkina Faso, Cameroon, Gabon, Japan, Mexico, Norway, South Korea, Slovenia, Uruguay.

Britain, France, Madagascar, Kyrgyzstan and Angola did not vote.