Morning Buzz: May 16, 2007

This morning's top stories:

• The violence between rival Palestinian parties in the Gaza Strip continues to escalate. Hamas militants killed six bodyguards from the Fatah movement and mistakenly ambushed one of their own jeeps, killing five, the AP reports.
• The second Republican presidential candidate debate, held Tuesday night at the University of South Carolina, was considerably more confrontational than the first one. Read quotes from the debate.
• The governing board of the World Bank resumes a meeting today that will ultimately decide the fate of its president, Paul Wolfowitz, who made an emotional appeal for his job.
• Martin Luther King Jr.'s oldest daughter died yesterday of unknown causes. She was 51.
• An image snagged by the Hubble Space Telescope has offered astronomers a powerful piece of evidence of the existence of vast amounts of "dark matter" in the universe.