Israel fired artillery shells containing white phosphorus in its recent conflict with Hizbollah militants in the Lebanon, according to an official investigation by the United Nations.
White phosphorus is banned under the Geneva Convention when used against civilians or in civilian areas, although Israel insists that the shells were directed against solely military targets.
However, the UN team failed to find any evidence that Israel used depleted uranium, enriched uranium or any other radioactive material in bombs dropped on Lebanon during the month-long war, which ended on 14 August.
Achim Steiner, under-secretary general and executive director of the UN Environment Programme (UNEP), said that samples taken by scientists had confirmed the use of white phosphorus in artillery and mortar ammunition.
Mr Steiner also said that the scientific analysis found no evidence of penetrators or other metallic bomb components made of depleted or enriched uranium, as claimed by two British activists in a report last month.
The samples taken by the UN for analysis were collected between 30 September and 21 October. Three independent laboratories in Europe undertook the tests on behalf of the UN.
The findings conflict with a report by Chris Busby, a Green Party activist, and his colleague Dai Williams, an occupational psychologist, who claimed to have found evidence of enriched uranium in a sample collected from a bomb site in southern Lebanon.
The sample was sent for analysis at the Harwell Laboratory in Oxfordshire, which is used by the Ministry of Defence. "We are concerned that UNEP don't know what they are doing. Earlier [in 2001] they were useless at finding depleted uranium in Kosovo due to wrong choice of instrumentation," Dr Busby said.
* The UN secretary general, Kofi Annan, has called for a freeze on the use of cluster bombs, saying they had "atrocious, inhumane effects" on civilians.