Oil prices have fallen 1% after increasing stockpiles of crude and refined fuel led to fears of another glut.
Brent crude LCOc1 dropped 65 cents to touch at $46.96 a barrel, while US West Texas Intermediate (WTI) crude CLc1 dropped 71 cents to reach at $45.24 a barrel, reported Reuters.
The news agency reported Market intelligence firm Genscape as saying that Oklahoma delivery centre for US crude futures had seen a supply increase of 26,460 barrels last week.
A coup attempt in Turkey could not support the market given that Istanbul's Bosphorus Strait reopened following a closure for a short time.
This strait handles about 3% of worldwide oil shipments, primarily from the Caspian region and Black Sea ports.
Jim Ritterbusch of Ritterbusch & Associates was quoted by the news agency as saying: "We are maintaining a bearish trading stance as we still see an ultimate price downdraft in WTI and Brent to about $37 and $38 areas respectively."