Oil prices fell on Thursday, erasing the early gains that started in the Asian session, on renewed demand fears.
The US Energy Information Administration revealed yesterday that crude inventories fell 2 million barrels in the past week.
US output held unchanged last week at 10.7 million bpd, while remaining the world's top producer.
The dollar index fell against a basket of currencies by 0.1% to 93.7 points as of 19:21 GMT, after it hit a high of 93.9 and a low of 93.5.
As of 19:01 GMT, WTI October futures at Nymex fell 4.1% to $38.5 a barrel, after hitting a high of $40.4 and a low of $37.6.
Brent November futures fell 3.3% to $40.9 a barrel, with a high of $42.5 and a low of $39.9.