U.S. West Texas Intermediate (WTI) crude CLc1 futures dropped 2.1%, or 80 cents, to $37.16 a barrel at 0138 GMT, adding to a loss of 42 cents on Wednesday.
Brent crude LCOc1 futures fell 1.5%, or 61 cents, to $40.10 a barrel. The benchmark contract declined 25 cents on Wednesday.
Worries about fuel demand rose after a surge in coronavirus cases led Beijing to cancel flights and shut schools and several U.S. states, including Texas, Florida and California, reported sharp increases in new cases.
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