Sen. Hillary Rodham Clinton last night ripped into 2008 White House contender John Edwards - her first direct assault on any of her potential Democratic presidential rivals.

Clinton's surprising broadside came just hours after Edwards, in Harlem, delivered a sharp condemnation - clearly aimed at Clinton, although he didn't mention her by name - against those who fail to "speak out" against the war in Iraq.

"Silence is betrayal, and I believe it is a betrayal not to speak out against the escalation of the war in Iraq," Edwards told a crowd at Manhattan's Riverside Church, where Martin Luther King had declared his opposition to the Vietnam War.

"If you're in Congress and you know that this war is going in the wrong direction . . . it is no longer OK to study your options and keep your own private counsel," he said.

"Silence is betrayal. Speak out and stop this escalation now."

Word from those who work for Sen. Barack Obama is that he will take the first step toward the U.S. Presidency and file the papers with the Federal Election Commission this week. It will open an exploratory committee that declares his intentions to be a candidate for president, NBC 5's Mary Ann Ahern reported. A more formal announcement is still several weeks away.