We know that the Israelis used American "bunker-buster" bombs on Hizbollah's Beirut headquarters. We know that they drenched southern Lebanon with cluster bombs in the last 72 hours of the war, leaving tens of thousands of bomblets which are still killing Lebanese civilians every week. And we now know - after it first categorically denied using such munitions - that the Israeli army also used phosphorous bombs, weapons which are supposed to be restricted under the third protocol of the Geneva Conventions, which neither Israel nor the United States have signed.

But scientific evidence gathered from at least two bomb craters in Khiam and At-Tiri, the scene of fierce fighting between Hizbollah guerrillas and Israeli troops last July and August, suggests that uranium-based munitions may now also be included in Israel's weapons inventory - and were used against targets in Lebanon. According to Dr Chris Busby, the British Scientific Secretary of the European Committee on Radiation Risk, two soil samples thrown up by Israeli heavy or guided bombs showed "elevated radiation signatures". Both have been forwarded for further examination to the Harwell laboratory in Oxfordshire for mass spectrometry - used by the Ministry of Defence - which has confirmed the concentration of uranium isotopes in the samples.

Dr Busby's initial report states that there are two possible reasons for the contamination. "The first is that the weapon was some novel small experimental nuclear fission device or other experimental weapon (eg, a thermobaric weapon) based on the high temperature of a uranium oxidation flash ... The second is that the weapon was a bunker-busting conventional uranium penetrator weapon employing enriched uranium rather than depleted uranium." A photograph of the explosion of the first bomb shows large clouds of black smoke that might result from burning uranium.

Enriched uranium is produced from natural uranium ore and is used as fuel for nuclear reactors. A waste productof the enrichment process is depleted uranium, it is an extremely hard metal used in anti-tank missiles for penetrating armour. Depleted uranium is less radioactive than natural uranium, which is less radioactive than enriched uranium.

Israel has a poor reputation for telling the truth about its use of weapons in Lebanon. In 1982, it denied using phosphorous munitions on civilian areas - until journalists discovered dying and dead civilians whose wounds caught fire when exposed to air.

I saw two dead babies who, when taken from a mortuary drawer in West Beirut during the Israeli siege of the city, suddenly burst back into flames. Israel officially denied using phosphorous again in Lebanon during the summer - except for "marking" targets - even after civilians were photographed in Lebanese hospitals with burn wounds consistent with phosphorous munitions.

Then on Sunday, Israel suddenly admitted that it had not been telling the truth. Jacob Edery, the Israeli minister in charge of government-parliament relations, confirmed that phosphorous shells were used in direct attacks against Hizbollah, adding that "according to international law, the use of phosphorous munitions is authorised and the (Israeli) army keeps to the rules of international norms".

Asked by The Independent if the Israeli army had been using uranium-based munitions in Lebanon this summer, Mark Regev, the Israeli Foreign Ministry spokesman, said: "Israel does not use any weaponry which is not authorised by international law or international conventions." This, however, begs more questions than it answers. Much international law does not cover modern uranium weapons because they were not invented when humanitarian rules such as the Geneva Conventions were drawn up and because Western governments still refuse to believe that their use can cause long-term damage to the health of thousands of civilians living in the area of the explosions.

American and British forces used hundreds of tons of depleted uranium (DU) shells in Iraq in 1991 - their hardened penetrator warheads manufactured from the waste products of the nuclear industry - and five years later, a plague of cancers emerged across the south of Iraq.

Initial US military assessments warned of grave consequences for public health if such weapons were used against armoured vehicles. But the US administration and the British government later went out of their way to belittle these claims. Yet the cancers continued to spread amid reports that civilians in Bosnia - where DU was also used by Nato aircraft - were suffering new forms of cancer. DU shells were again used in the 2003 Anglo-American invasion of Iraq but it is too early to register any health effects.

"When a uranium penetrator hits a hard target, the particles of the explosion are very long-lived in the environment," Dr Busby said yesterday. "They spread over long distances. They can be inhaled into the lungs. The military really seem to believe that this stuff is not as dangerous as it is." Yet why would Israel use such a weapon when its targets - in the case of Khiam, for example - were only two miles from the Israeli border? The dust ignited by DU munitions can be blown across international borders, just as the chlorine gas used in attacks by both sides in the First World War often blew back on its perpetrators.

Chris Bellamy, the professor of military science and doctrine at Cranfield University, who has reviewed the Busby report, said: "At worst it's some sort of experimental weapon with an enriched uranium component the purpose of which we don't yet know. At best - if you can say that - it shows a remarkably cavalier attitude to the use of nuclear waste products."

The soil sample from Khiam - site of a notorious torture prison when Israel occupied southern Lebanon between 1978 and 2000, and a frontline Hizbollah stronghold in the summer war - was a piece of impacted red earth from an explosion; the isotope ratio was 108, indicative of the presence of enriched uranium. "The health effects on local civilian populations following the use of large uranium penetrators and the large amounts of respirable uranium oxide particles in the atmosphere," the Busby report says, "are likely to be significant ... we recommend that the area is examined for further traces of these weapons with a view to clean up."

This summer's Lebanon war began after Hizbollah guerrillas crossed the Lebanese frontier into Israel, captured two Israeli soldiers and killed three others, prompting Israel to unleash a massive bombardment of Lebanon's villages, cities, bridges and civilian infrastructure. Human rights groups have said that Israel committed war crimes when it attacked civilians, but that Hizbollah was also guilty of such crimes because it fired missiles into Israel which were also filled with ball-bearings, turning their rockets into primitive one-time-only cluster bombs.

Many Lebanese, however, long ago concluded that the latest Lebanon war was a weapons testing ground for the Americans and Iranians, who respectively supply Israel and Hizbollah with munitions. Just as Israel used hitherto-unproven US missiles in its attacks, so the Iranians were able to test-fire a rocket which hit an Israeli corvette off the Lebanese coast, killing four Israeli sailors and almost sinking the vessel after it suffered a 15-hour on-board fire.

What the weapons manufacturers make of the latest scientific findings of potential uranium weapons use in southern Lebanon is not yet known. Nor is their effect on civilians.

The main article is http://news.independent.co.uk/world/fisk/article1935945.ece

A comment from Chris Bellamy, professor of military science and doctrine at Cranfield University is at http://news.independent.co.uk/world/middle_east/article1935931.ece

The report follows research by Dr. Chris Busby of LLRC (also of environmental consultancy Green Audit and the European Committee on Radiation Risk) using samples recovered from the Lebanon by Dai Williams of Eos.

The immediate question (Robert Fisk and Professor Bellamy both pose it) is Why? What is the point of putting enriched Uranium in bombs? The Independent report addresses a couple of possibilities but to the Low Level Radiation Campaign it seems far more likely that the enriched Uranium is meant to mask the use of Depleted Uranium, especially bearing in mind the provenance of much of Israel's arsenal. The American military has been concerned about bad publicity since at least 1991 — DU rounds may become politically unacceptable and thus be deleted from the arsenal. (see this link for the full 1991 memorandum from a high-ranking US army officer: http://www.llrc.org/du/subtopic/rosalie.htm#ziehm, also cited in http://www.llrc.org/du/subtopic/faheyquotes.htm#ziehm).

Following the use of Depleted Uranium armour piercing rounds in the first Gulf War and in the Balkans conflict it was relatively easy to detect DU in environmental samples. This is because of the tell-tale ratio of U-238 to U-235. The link to subsequent increases in cancer and birth defects is intuitively obvious and scientifically credible, given that it is now generally acknowledged that "dose" from internal exposure to sources such as DU is a virtually meaningless concept.

There have been suggestions that confusion about DU in subsequent campaigns may have been caused by the use of Uranium metal (in e.g. bunker busters) in its naturally occurring proportions — i.e. undepleted. We may now have an explanation. A relatively small number of rounds or bombs made with slightly enriched Uranium — as we now see in the Lebanon — would mask a much larger number of  DU weapons by increasing the amount of U-235 in the environment towards its natural abundance relative to U-238. (The natural proportions of these isotopes are U-235 0.7 percent; U-238 99.3 percent.) The military will then claim that the Uranium found after a conflict is the result of high explosives and soil disturbance unless, that is, someone with Dai Williams' courage gets samples from the conflict area before reconstruction work buries and redistributes the evidence.

Green Audit's report is at http://www.llrc.org/du/subtopic/lebanrept.pdf

We conclude by repeating, as we have for the last ten years, that Depleted Uranium weaponry is illegal because the radioactive aerosols produced by the impacting rounds have indiscriminate health effects. This contravenes the UN Convention on prohibitions or restrictions on the use of certain conventional weapons which may be deemed to be excessively injurious or to have indiscriminate effects (1980). (see http://www.llrc.org/du/subtopic/medact#illegal). The same must apply to enriched Uranium and the health effects must be assumed to be greater, in proportion to its mass, because particles of U-235 will deliver more energy to body tissue than similar sized particles of U-238. LLRC has photographed multiple radiation tracks from particles in an air filter recently recovered from a Lebanese ambulance. They indicate that the source is far more active than (depleted) U-238. The area of filter so far examined is small, suggesting that such particles are fairly common in that environment. We shall produce further briefings on this issue.