Washington:  Senator Hillary Clinton tried again on Sunday to explain her reference last week to Robert Kennedy's assassination, while her campaign aides accused Senator Barack Obama's advisers of taking the comment out of context and exploiting it.

In an interview in South Dakota on Friday, Clinton was discussing why she is still seeking her party's presidential nomination when she referred to the assassination of Kennedy - then, like her, a senator from New York - on June 5, 1968, as he celebrated his victory in the California primary. She used the June date to illustrate how long the Democratic race has gone on in past cycles, and she apologised after it caused an immediate furore. But on Sunday she said the remarks had been misinterpreted.

'Unthinkable'

"Almost immediately, some took my comments entirely out of context and interpreted them to mean something completely different - and completely unthinkable," Clinton wrote in an article published in the New York Daily News, whose publisher, Mort Zuckerman, is a longtime friend of the Clintons.

"I want to set the record straight: I was making the simple point that given our history, the length of this year's primary contest is nothing unusual," Clinton said. She went on to say that she "was deeply dismayed and disturbed" that her comment about Kennedy's shooting would be construed as anything other than a historical reference.

Her campaign chairman, Terence McAuliffe, was more explicit in his criticism. "It's unfortunate - a hyped-up press over Memorial Day weekend, the Obama campaign inflaming it, tried to take these words out of context," he said on "Fox News Sunday."

On Friday, a spokesman for the Obama campaign, Bill Burton, said Clinton's statement was "unfortunate and has no place in this campaign". On Saturday, Obama told a Puerto Rican radio station that he took Clinton at her word when she said she meant no harm in invoking Kennedy's assassination.

Neither Clinton nor McAuliffe - nor Obama or his spokesmen - mentioned the concern about his safety, particularly among African Americans, that the reference to Kennedy touched on. In a Washington Post-ABC News poll taken in March, nearly six in 10 Americans said they were worried that someone might try to harm Obama if he were the nominee - more than double the percentage who said they were worried about the same for Senator John McCain, the presumptive Republican nominee.

Among African Americans, the concern was even greater: More than eight in 10 said they would be worried about Obama's safety, including 55 per cent who said they would be "very concerned".

- Los Angeles Times-Washington Post News Service