Investing.com - Oil prices fell to their lowest level in more than five weeks on Tuesday, as investors looked ahead to the release of fresh weekly data on U.S. commercial crude inventories.
The American Petroleum Institute is due to release its weekly report for the week ended Oct. 19 at 4:30 PM ET (2030 GMT), amid expectations of an increase of about 3.5 million barrels.
If confirmed, it would be the fifth-straight weekly climb in domestic crude supplies.
The Energy Information Administration's more-closely-followed report will be released Wednesday.
November West Texas Intermediate crude, the U.S. benchmark contract, sank $1.28, or 1.85%, to $67.89 a barrel at 9:05 AM ET (1305 GMT) on the New York Mercantile Exchange, its lowest since Sept. 14.
Meanwhile, international benchmark Brent crude oil futures were at $78.05 a barrel on ICE Futures Europe, down $1.78, or about 2.2%.
Prices came under pressure after Saudi Arabia pledged to play a "responsible role" in energy markets, despite its increasing isolation over the killing of Saudi journalist Jamal Khashoggi.
Investors suspect the latest development could undermine the leadership of Crown Prince Mohammed bin Salman and has the risk of eventually destabilizing the oil-rich kingdom.
A global equity rout was also seen weighing on sentiment, putting pressure on assets perceived as risky, including most commodities.
In other energy trading, gasoline futures dropped 2.1% to $1.866 a gallon, while heating oil declined 1.7% to $2.278 a gallon.
Natural gas futures inched up 0.8% to $3.163 per million British thermal units.