Oil futures settled at their lowest level in more than two weeks on Monday as data showing weaker-than-expected industrial production in China and a decline for Shanghai’s stock market raised concerns that demand for crude from the world’s second-largest consumer will weaken.

Traders also braced for more volatility and possibly lower oil prices in coming weeks. Goldman Sachs Group Inc. said last week that U.S. oil prices could fall to as low as $20 a barrel to clear out a global supply glut.

October West Texas Intermediate crude settled at $44 a barrel, down 63 cents, or 1.4%, on the New York Mercantile Exchange, marking its lowest settlement since Aug. 27. October Brent crude on London’s ICE Futures exchange, which expires Tuesday, saw prices fall $1.77, or 3.7%, to $46.37 a barrel. Both WTI and Brent crude futures lost around 3% last week. “Crude oil continues to fall in reaction to a worse-than-expected Chinese industrial production report, coupled with the fear of a U.S. rate hike from the Fed this week,” said Tim Evans, chief market strategist at Long Leaf Trading Group.

The U.S. Federal Open Market Committee meeting on Sept. 16-17 is expected to be the main theme for financial markets this week and any fluctuations in the dollar will also affect oil prices. A strengthening of the U.S. dollar has generally been bearish for oil prices. However, market expectations of a U.S. interest-rate increase this week have been tempered by the recent turmoil in global markets and worries over economic growth. China’s stock market fell on Monday. Data released over the weekend showed that factory production and fixed-asset investment in China were both weather than expected in August.

Even so, oil prices have found some support in recent sessions. On Friday, Baker Hughes reported that the number of active U.S. oil-drilling rigs fell by 10 to 652 rigs last week, the second consecutive week of declines, raising hopes that lower oil prices may have started to affect shale-oil producers. And in a monthly report issued Monday, the Organization of the Petroleum Exporting Countries cut its forecast of oil supplies from nonmember countries this year by about 72,000 barrels a day to 880,000 barrels a day, citing lower-than-expected output in the U.S.

For now, the global oil market continues to be oversupplied, however. In the U.S., refineries are beginning to slow production of gasoline following the end of the summer-driving season, which could contribute to a further rise in crude stockpiles.