Renewed concerns that tensions could flare up between Russian and Ukraine pushed U.S. stocks sharply lower Tuesday. Several traders pointed to news reports of a buildup in Russian troops on the Ukraine border and comments from a Polish politician that reportedly said Russia was poised to invade or pressure Ukraine's eastern border as catalysts for the selling.

On Tuesday:

The Dow lost 139.81 points, or 0.8 percent, to close at 16,429.47.

The Standard & Poor's 500 index fell 18.78 points, or 1 percent, to 1,920.21.

The Nasdaq composite fell 31.05 points, or 0.7 percent, to 4,352.84.

For the week:

The Dow is down 63.90 points, or 0.4 percent.

The S&P 500 is down 4.94 points, or 0.3 percent.

The Nasdaq is up 0.19 of a point, effectively unchanged.

For the year:

The Dow is down 147.19 points, or 0.9 percent.

The S&P 500 index is up 71.85 points, or 3.9 percent.

The Nasdaq is up 176.25 points, or 4.2 percent.