Oil prices fell by 2% this evening after data showing a rise in US stockpiles and weak demand added to wider economic concerns that have affected prices over the past week. Brent fell $2.62 to $113.84 a barrel, while US crude dropped $1.71 to $92.08.

US petrol stockpiles rose sharply and demand over the past four weeks fell 3.6% compared with a year ago, according to the US Energy Information Administration. This added to concerns about tepid consumption in the midst of the peak summer demand period.

Overall crude inventories increased as the US government released more oil from the Strategic Petroleum Reserve as part of a co-ordinated effort with the International Energy Agency to make up for a disruption in supplies from Libya.

Earlier in the day, oil shrugged off positive data showing US private employers added more jobs than expected in July as analysts said the focus remained on the longer term challenges for the world's largest economy and the euro zone's troubles.