Newspaper reports that Israel built, exploded 'dirty bomb' with nuclear material in a test

A major Israeli newspaper says the government built and exploded a "dirty bomb" with nuclear material inside it to see how such an attack would affect the country.

The Haaretz daily newspaper on Monday quoted researchers as saying the tests were for defensive purposes only. It quoted them as saying that high radiation was found at the center of blasts while small particles carried by wind don't pose serious danger.

The newspaper said the experiment ended last year. It said the blast took place in Israel's southern desert.

So-called "dirty bombs" are traditional explosives laced with nuclear material intended to contaminate a wide area.

Israeli defense officials refused to comment on Monday's report. Israel has never declared what is widely considered to be an extensive nuclear weapons program.