"The government has total confidence in the security forces, in the army and the chief of staff," he told the opening of the weekly cabinet meeting.
"Explanations need to be asked from those who have fired systematically and for a long time against (Israeli) civilians without those who teach morality seeing the need for the creation of a commission," he added.
The UN General Assembly on Friday overwhelmingly passed a resolution urging an immediate end to all acts of Israeli and Palestinian violence, including an Israeli offensive in the Gaza Strip and Palestinian rocket firing into Israel.
The text also asked the UN secretary general to set up a fact-finding mission to probe Israel's shelling of private homes in the Gaza town of Beit Hanun on November 8 which killed 19 Palestinians, mainly children and women.
Some 156 countries, including the 25-member European Union, voted in favor of the non-binding resolution, introduced by Qatar on behalf of Arab states.
Seven -- the United States, Israel, Australia, Nauru, Palau, the Marshall Islands and Micronesia -- voted against while six, including Canada, abstained.
Olmert has said a technical error was responsible for the artillery fire in Beit Hanun and Israel has expressed regret for the "tragedy".

Copyright AFP (Agence France-Presse), 2006