After a few minutes of trading, the Dow Jones industrial average had fallen 0.6 percent, the broad S&P 500 index 0.3 percent and the tech-heavy Nasdaq composite index 0.4 percent.
Wednesday ended with a slight rise after the US Treasury Department reshuffled its bond portfolio in an effort to push down long-term market interest rates.
But that breathing space looks set to be short-lived after analysts pointed to remaining problems, including uncertainty around the national debt, the policy rate and the protracted conflict with Iran.
Market interest rates are rising sharply again and, in parallel, the oil price is increasing by just over 2 percent to $93.7 per barrel of North Sea oil.
