New York - An inquiry into damage inflicted to UN properties and people who may have been killed there during the recent conflict between Israel and Hamas in the Gaza Strip is expected to be completed later this month, a UN spokeswoman said Monday.

The investigation by the UN board of inquiry was ordered by UN Secretary General Ban Ki-moon after the UN suffered extensive damage to its offices and schools for Palestinian children in Gaza as a result of Israeli airstrikes.

UN spokeswoman Marie Okabe said other efforts were also ongoing to determine the facts of the conflict from December 27 to January 19.

The Geneva-based Human Rights Council planned to launch its own investigation into violations of international human rights law.

Okabe said the UN board of inquiry was reviewing and looking into specific incidents in Gaza "in which death or injuries occurred at, and/or damage was done to, United Nations premises."

Amnesty International on Monday sent a letter to Ban, signed by 16 experienced investigators, judges and human rights advocates calling for an international investigation of alleged abuses in international law in Gaza. The letter was also sent to the UN Security Council.

Amnesty said the 16-member panel should be mandated to carry out a "prompt, thorough, independent and impartial investigation of all allegations of serious violations of international humanitarian law committed by all parties to the conflict."

It said the panel should recommend as appropriate "prosecution of those responsible for gross violations of the law by the relevant authorities."

The letter said the panel should investigate "all serious violations of international humanitarian law committed by all parties to the conflict" and should not be limited only to attacks on UN premises.

Those signing the letter to Ban were investigators of crimes committed in the former Yugoslavia, Kosovo, Darfur, Rwanda, Sierra Leone, South Africa, East Timor, Lebanon and Peru.

They included Antonio Cassese, former president and judge of the International Criminal Tribunal for the former Yugoslavia; Richard Goldstone, former chief prosecutor of the same tribunal and the tribunal for Rwanda; former Irish President Mary Robinson, former UN Commissioner for Human Rights; and Bishop Desmond Tutu of South Arrica. (dpa)