CBS reported last night that Israel exploded the small atomic bomb whose fireball may have been seen in the skies near South Africa Sept. 22 by an American surveillance satellite.

"CBS News has learned that Israel exploded a nuclear bomb last Septemeber in the Atlantic Ocean off the coast of South Africa," the report said, "which was conducted with the help and cooperation of the South African government."

A senior State Department official said last night that there is "no corroborative evidence" that Israel was involved in a nuclear test explosion, if indeed there was such a test last September. The official pointed out that a U.S. study was unable to conclude if the September incident was a test.

The CIA has told key congressional committees that if there was a test near South Africa last Sept. 22, Israel was its leading candidate as the source. The CIA said South Africa was its second candidate, adding that it was not impossible that the test was a joint undertaking.

CBS said it had obtained "major contents" of a book soon to be published in Hebrew by Israeli journalists Eli Teicher and Ami Dor-On that states that Israel has been making nuclear weapons for at least 10 years. CBS said the books says Israel "has an arsenal including several dozen atomic bombs and several hydrogen bombs."

The network went on to say that South Africa first offered Israel the chance to test an atomic bomb on its soil in 1966. CBS said Israel declined the offer until last year, when "the Israeli military had to know if its bomb worked."