Arab nations accused Israel on Monday of blasting Gaza with ammunition containing depleted uranium and urged the International Atomic Energy Agency to investigate reports that traces of it had been found in victims of the shelling. In a letter on behalf of Arab ambassadors accredited in Austria, Prince Mansour Al-Saoud, the Saudi Ambassador, expressed "our deep concern regarding the information ... that traces of depleted uranium have been found in Palestinian victims." A final draft of the letter was made available to The Associated Press on Monday. It urgently requested IAEA Director General Mohamed ElBaradei to "carry out a radiological and physical assessment in order to verify the presence of depleted uranium in the weaponry used by Israel ... in the Gaza Strip." Officials at the Israeli mission to the IAEA said they were in no position to comment without having seen the letter. IAEA spokeswoman Melissa Fleming confirmed receipt of the letter and said a response might be issued later in the day. The letter - which spoke of "medical and media sources" as the origin of its allegations - appeared to be alluding to health concerns related to depleted uranium, but the effects of exposure to the substance are unclear. An IAEA article on the issue says that while the substance "is assumed to be potentially carcinogenic ... the lack of evidence for a definite cancer risk in studies over many decades is significant and should put the results of assessments in perspective." Still, says the article, "there is a risk of developing cancer from exposure to radiation emitted by ... depleted uranium. This risk is assumed to be proportional to the dose received." It is not the first time Israel has been accused of using ordnance containing depleted uranium, which makes shells and bombs harder and increases their penetrating power. Syria, which is being investigated by the Vienna-based agency for alleged secret nuclear activities, says traces of uranium found by IAEA experts at a site reportedly bombed by IAF jets on Sept. 6, 2007 likely came from bombs or missiles used by Israel. Israel has denied using such weaponry in that raid, and on Monday, two diplomats accredited to the IAEA and familiar with its Syria investigations told AP that the agency had virtually ruled out Israeli munitions as the source of the uranium. They asked for anonymity for discussing confidential information. The IAEA investigation is based in part on intelligence from the US, Israel and a third, unidentified country, alleging that the bombed site was a nearly completed nuclear reactor built with North Korean help and meant to produce plutonium - which can be used as the payload of nuclear weapons. The uranium traces were revealed by an analysis of environmental samples collected by IAEA experts during a visit to the site, in a remote part of the Syrian desert. Since that initial trip in June 2008, Syria has refused or deflected requests for follow up inspections both to the site and others allegedly linked to it.