The concerns were many, one of which involved oil prices, again making a move on the $70-a-barrel plateau.

The Dow Jones industrial average plunged 185.58 points, or 1.37 percent, to close at 13,360.26. The Nasdaq composite fell 28 points, or 1.07 percent, to 2,588.96 and the Standard and Poor's 500 was down 19.63 points, or 1.29 percent, at 1,502.56.

The volume on the New York Stock Exchange was 1.4 billion shares, of which 841 stocks gained and 2,463 declined.

Crude oil futures rose, with the August contract up 58 cents at $69.23 a barrel with investors still bothered by a strike in Nigeria.

Bonds gained with the 10-year note up 10/32, or $3.13 for every $1,000 invested, to yield 5.15 percent.

The dollar was mixed. The euro was recently at $1.3464 from $1.3403 late Thursday, while the dollar was at 123.84 yen from 123.60.