The Dow Jones industrial average fell in early trading and then rose as much as 35 points before pulling back again late in the day. Though the economy seems to be improving, analysts say renewed political uncertainty could keep indecisive investors from making major commitments.

"Investors are very nervous about continued terrorist activity, but at the same time, they are showing more confidence in the economy and the equity market," said Peter Dunay, chief market strategist at Wall Street Access. "So we have a little battle of the pros and cons here."

The Dow closed down 71.04, or 0.7 percent, at 9,619.42, having declined in four of the past five sessions.

The broader market also finished lower. The Nasdaq composite index fell 17.73, or 0.9 percent, to 1,881.92. The Standard & Poor's 500 index declined 8.79, or 0.8 percent, to 1,033.65.

In Turkey, two truck bombs exploded outside London-based HSBC and the British consulate, killing at least 25 people and wounding nearly 400. The explosions, which came during President Bush's trip to Britain, were blamed on the al-Qaida terrorist network.

Terrorism had receded as a factor in stock trading, but the bombings of two synagogues in Turkey during the weekend and yesterday's attacks reminded world markets of the still-present dangers.

Declining issues outnumbered advancers about 8 to 5 on the New York Stock Exchange. Consolidated volume was light at 1.68 billion shares, compared with 1.73 billion traded Wednesday.

The Russell 2000 index, which tracks smaller company stocks, fell 2.54, or 0.5 percent, to 523.08.