Brent crude fell $2.18, or 5.2 percent, to $39.83 in early afternoon trade, and earlier slipped to $39.61, the lowest since June 25. US West Texas Intermediate (WTI) crude dropped $2.99 or 7.5 percent, to $36.78.

On Monday, crude fell after Saudi Arabia’s state oil company Aramco cut the October official selling prices for its Arab light oil, a sign demand may be stuttering.

“The price weakness is continuing today,” said Eugen Weinberg, analyst at Commerzbank. “We believe this is attributable first and foremost to demand concerns