Scientists studying samples of soil thrown up by Israeli bombing in Lebanon have shown high radiation levels, suggesting uranium-based munitions were used, a British newspaper reports.

The samples were taken from two bomb craters in Khiam and At-Tiri and have been sent for further analysis to the Harwell laboratory in Oxfordshire, southern England, for mass spectrometry used by the Ministry of Defence, The Independent said.

The samples thrown up by Israeli heavy or guided bombs showed "elevated radiation signatures," Chris Busby, the British scientific secretary of the European Committee on Radiation Risk, was quoted as saying.

Britain's Ministry of Defence has confirmed the concentration of uranium isotopes in the samples, the newspaper said.

In his initial report, Busby said there were two possible reasons for the contamination.

"The first is that the weapon was some novel small experimental nuclear fission device or experimental weapon (eg. a thermobaric weapon) based on the high temperature of a uranium oxidation flash," it said.

"The second is that the weapon was a bunker-busting conventional uranium penetrator weapon employing enriched uranium rather than depleted uranium," Busby was quoted as saying.

A photograph of the explosion of the first bomb shows large clouds of black smoke that might result from burning uranium, the newspaper said.

The 34-day Israeli offensive against Hezbollah guerrillas in Lebanon left at least 1,287 people, nearly all civilians, dead and 4,054 wounded, according to an AFP count based on official Lebanese figures.

At least 1,140 civilians -- 30 percent of them children under 12 -- have been killed along with 43 Lebanese army and police troops in the offensive, the state High Relief Committee said.