NEW YORK (AFP) - Wall Street stocks fell on Tuesday (Sept 13) on lower oil prices and the murky outlook surrounding US monetary policy.

Tuesday marked the third straight day that major US indices experienced moves of one percent or more.

Analysts attributed the swings to contradictory signals from US Federal Reserve officials on the likelihood of an imminent interest rate hike.

"It's been a yo-yo the last few days," said Bill Lynch, director of investments at Hinsdale Associates.

"We're going to be in a period between now and the Fed's meeting next week where there could be increased volatility."

At the closing bell, the Dow Jones Industrial Average was at 18,066.89, down 1.4 per cent.

The broad-based S&P 500 dropped 1.5 per cent to 2,127.04, while the tech-rich Nasdaq Composite Index shed 1.1 per cent to 5,155.25.