Oil prices have experienced a rise due to a drop in US crude stocks by 559,000 barrels in the week ending 9 September. 

Brent crude futures were up 20 cents and traded at $46.05 per barrel, while the US West Texas Intermediate futures rose 6 cents at $43.64 a barrel, Reuters reported.

The fall in crude inventories is against analysts expectations of an increase of 3.8 million barrels.

"The market seems to be more concerned at the moment about the possibility of a sharp increase of supply from Libya."

CMC Markets chief market analyst Ric Spooner told the news agency: "It's good news at this time of the year to see a draw like that (in crude stocks).

"But the market seems to be more concerned at the moment about the possibility of a sharp increase of the supply from Libya."

During the last five trading sessions, crude prices have dropped by around 8% and concerns are still growing due to a return in supplies expected from Libya and Nigeria.

Libya is planning to lift heavy security measures at its port of Zueitina, with the country's crude exports then potentially beginning. More than half of the country’s exports are normally routed through es-Sidra, Zueitina, Ras Lanuf and Brega terminals which were seized by the Libyan National Army recently.

Offers for October-loading Qua Iboe crude have emerged and Nigerian supplies are expected to return.