Oil prices fell sharply on Thursday after a report showed U.S. crude inventories rose more than expected, stoking concerns about a global supply glut.

Brent crude futures fell $1.01 to $71.08 a barrel by 10:45 a.m. EST (1545 GMT). U.S. West Texas Intermediate (WTI) crude futures fell $1.21 to $60.60 a barrel.

U.S. crude inventories rose by 3.2 million barrels in the week to Oct. 26, the Energy Information Administration (EIA) said, exceeding analysts’ expectations for an increase of 2.3 million barrels.

The rise in inventories comes as U.S. production remains near record highs, adding to concerns about oversupply.

“The market is reacting to the inventory numbers, which were definitely bearish,” said Phil Flynn, an analyst at Price Futures Group in Chicago. “We’re seeing a pretty significant sell-off.”

Adding to the bearish sentiment, the Organization of the Petroleum Exporting Countries (OPEC) and its allies, including Russia, are expected to discuss a possible increase in production at their meeting in Vienna next month.

“The market is worried that OPEC+ will decide to increase production, which would exacerbate the oversupply situation,” said Olivier Jakob, an analyst at Petromatrix.

The price drop comes despite ongoing concerns about supply disruptions from Iran, which is facing U.S. sanctions that are due to take effect on Nov. 4.

“The market is still concerned about the impact of the Iran sanctions, but the focus is now on the oversupply situation,” said Jakob.