UNITED NATIONS, Feb 26 (Reuters) - The General Assembly on Friday demanded credible Israeli and Palestinian investigations into UN allegations of war crimes in last year's Gaza war, reflecting concerns that the probes so far have fallen short.

The United Nations' 192-nation assembly of member states approved the nonbinding Arab-drafted resolution with 98 votes in favor, seven against and 31 abstentions. Some 56 nations did not participate in the vote.

The Palestinian Authority's permanent observer to the United Nations, Riyad Mansour, blamed a massive snowstorm that closed down schools and many businesses in New York for the poor attendance at the time of the vote. He added that the vote reflected overwhelming support for the Arab resolution.

The resolution calls for investigations that are independent, credible and in conformity with international standards into charges raised in a UN report last September by a panel headed by South African jurist Richard Goldstone.

The Goldstone report said the Israeli army and Palestinian armed groups committed war crimes during the conflict from late December 2008 to mid-January 2009, but focused more on Israel.

Unlike an earlier resolution the assembly adopted in November 2009, Friday's resolution set no deadline for the completion of the investigations.

It did, however, request a report on Israeli and Palestinian compliance with the resolution from UN Secretary-General Ban Ki-moon within five months, adding that further action by various UN bodies could follow.

More than 1,400 Palestinians and 13 Israelis died after Israel launched Operation Cast Lead in Gaza to try to end Hamas rocket fire against its cities. Critics charged that Israel used excessive and indiscriminate firepower but Israel blamed the militants for hiding among civilians.

INVESTIGATIONS SO FAR NOT SUFFICIENT

The United States and a few other countries like Micronesia and Nauru joined Israel in voting against Friday's resolution.

The assembly's November vote on the Goldstone Report divided the 27 European Union members into those that joined Israel and voted no, those that backed the Arabs and voted yes, and nations that abstained. No EU member voted against Friday's resolution, though some voted yes and some abstained.

Israel, the United States and other Western powers have called the Goldstone report biased and faulty. The Jewish state and Hamas militants in charge of the Gaza Strip have dismissed the idea that they were guilty of any war crimes.

The Israeli army has been conducting its own investigation of the allegations and the Palestinian Authority, which has no influence over the Gaza Strip, has promised to do so as well.

But Ban cast doubt on both sides' investigations in a letter he sent to the General Assembly earlier this month, withholding judgment on whether their probes were credible.

Israel's UN ambassador, Gabriela Shalev, reiterated her country's position that its investigations into the behavior of its soldiers during the conflict in Gaza were credible. She also made clear that Israel would not hesitate to take action in the future which it sees as necessary for self-defense.

We will do so with vigor -- against Hamas, Hezbollah, or any other terrorists, wherever they may be, she said.

US Deputy Ambassador Alejandro Wolff said questions about the war should be resolved by credible domestic investigations and their follow-up. But he reiterated the US view that the Goldstone report was deeply flawed.

British Ambassador Mark Lyall Grant said the Israeli investigations so far were not sufficient, and there are still some concerns. He added that the Palestinians had also so far not met their obligation to properly probe the allegations.