United States:Just days after a series of sharp exchanges in a debate last Thursday night, a tense row erupted between two top Democratic presidential candidates over the weekend as Illinois senator Barack Obama accused New York senator Hillary Clinton of spreading rumours that her campaign was in possession of potentially damaging information about her rival.
Political commentator Robert Novak wrote in his syndicated weekend column that "agents" of the Clinton campaign had been "spreading the word in Democratic circles that she has scandalous information about her principal opponent". Novak did not offer any further details about the allegedly negative information.
The Obama campaign lashed out at the report, saying it was "devoid of facts, but heavy on innuendo and insinuation of the sort to which we've become all too accustomed in our politics these past two decades".
Mr Obama challenged Mrs Clinton's campaign to either make the information public, "or concede the truth: that there is none".
Clinton campaign aides, in turn, denied any knowledge about what led to the item in the Novak column and accused Mr Obama of "echoing Republican talking points", and falling prey to a conservative columnist's attempts to pit Democrats against each other.
Mr Obama's campaign manager, David Plouffe, in an e-mailed statement, accused the Clinton campaign of evading the question of whether she was behind it.
"The Clinton campaign refuses to answer two simple, direct questions: are 'agents' of their campaign spreading these rumours? And do they have 'scandalous' information that they are not releasing?" Mr Plouffe wrote.
Further escalating the exchange, the Clinton campaign again mocked Mr Obama for betraying his promise to implement a "politics of hope" and said he was wasting his time on insubstantial matters.
"It's telling that the Obama campaign would rather spend the day throwing mud in Bob Novak's sandbox than talking about the issues," said Phil Singer, a Clinton spokesman.
None of the parties involved - including Novak - specified the substance of the rumours. He wrote that Ms Clinton had "decided not to use" the material. "This word-of-mouth among Democrats makes Obama look vulnerable and Clinton look prudent," Novak wrote. - (LA Times-Washington Post service)