(REUTERS) - Stocks fell on Thursday after the president of the European Central Bank expressed caution over more bond purchases to ease the region's debt crisis.

The Dow Jones industrial average was down 45.41 points, or 0.37 percent, at 12,150.96. The Standard & Poor's 500 Index dropped 8.86 points, or 0.70 percent, at 1,252.15. The Nasdaq Composite Index fell 19.27 points, or 0.73 percent, at 2,629.94.

(Reporting by Angela Moon; editing by Jeffrey Benkoe)