Violent protests have broken out at the summit of the Americas where US President George W. bush and 34 leaders are meeting in the city of Mar del Plata.

The violence came after a massive, peaceful march by about 10,000 demonstrators who listened to Venezuelan President Hugo Chavez urge them to fight U.S. policies, including a proposal to create a hemisphere-wide free trade agreement.

Meanwhile President George W. Bush has sidestepped questions in Mar del Plata about whether he owes the American people an apology for the role of administration officials in the CIA leak case.

He also refused to comment on calls for a staff shake-up.

"We're going through a very serious investigation. I have told you before that I'm not going to discuss the investigation until it's completed."

He also declined to say whether Karl Rove, his top political adviser, should remain in his job. Rove remains under investigation.

Special Counsel Patrick Fitzgerald is said to be considering whether Rove illegally misled investigators.

Lewis Libby, who was chief of staff for Vice President Dick Cheney has also been indicted.

Libby resigned after his indictment and pleaded not guilty to charges of obstruction of justice, two counts of lying to the FBI and two counts of committing perjury before a federal grand jury.

Source: CRI news