While world oil markets fret about Middle East tensions and booming demand from China and India, USdrivers are worrying about thecountry's hard-pressedrefineries. Fears of shortages at the pump are beginning to haunt America.

Last week, nine people were charged with stealing more than $100,000 (£55,000) worth of fuel after being arrested at a petrol station outside Houston at 2am. It was the latest sign of concern over rising fuel prices in gas-guzzling America.