As the White House said it would fully investigate Thursday's market debacle, U. S. markets closed with the Dow index down 1.33 percent Friday.

The Hill newspaper has reported that White House press secretary Robert Gibbs said the investigation would include considerations of sabotage.

Gibbs said, "I think that's, appropriately, why they're reviewing what may or may not have happened."

It was reported that Friday marked the third day of triple-digit losses in the week for the Dow Jones industrial average, which dropped 5.7 percent from Monday, shedding 771.40 points. But the week's major scare came Thursday, when the DJIA was briefly down 998 points for the day.

Markets that had run up since March 2009 hit the wall suddenly Tuesday. On Wednesday, losses moderated but Thursday, the DJIA dropped 998 points in mid-afternoon, off 9 percent, before recovering some ground, closing off
3.2 percent or 347 points.

They would look into a possibility that a trading error had derailed markets, Regulators have said.

The DJIA, by Friday's close, was off 139.89 points, to 10,380.43. The Standard & Poor's 500 index lost 1.53 percent, 17.27 points, to 1,110.88. The Nasdaq composite index dropped 2.33 percent, 54.00 points, to 2,265.64.

887 stocks advanced and 2,229 declined on a volume of 9.5 billion shares traded, on the New York Stock Exchange.

The unemployment rate rose from 9.7 to 9.9 percent, but the report was considered positive with the addition of 290,000 jobs to the economy, the Labor Department has said.

The benchmark 10-year Treasury note fell 7/32 to yield 3.429 percent.

From Thursday's $1.2629, a 12-month low, the euro rose slightly $1.2759. The dollar, against the yen, rose to 91.56 yen from Thursday's 90.25 yen. (With Inputs from Agencies)