A failed assassination attempt on Egypt's vice president in recent days left two of his bodyguards dead, though that information has yet to be confirmed on the ground in Cairo, Fox News reported quoting U.S. sources.

Such an attempt on the life of Omar Suleiman would mark an alarming turn in the uprising against the government of President Hosni Mubarak, who only recently named Suleiman as vice president in an effort to quell the unrest and possibly line up a successor.

White House Press Secretary Robert Gibbs declined to address the assassination reports.

"I'm not going to ... get into that question," Gibbs said.