Crude oil prices have risen still higher amid fears about continuing tensions between Iran, a key exporter, and the international community.
Disruption to Iranian oil supplies would hit global prices
Brent North Sea crude oil for delivery in June ended at $71.46 per barrel on Monday, rising for the ninth consecutive day.
Markets are anxious about the idea that the US could launch military strikes against Iranian nuclear sites.
Iran has pledged to carry on enriching uranium to fuel a nuclear reactor.
Iran, the world's fourth-largest oil producer, says it needs nuclear power to generate electricity, but western nations are concerned it wants to develop atomic weapons.
ABN Amro broker Lee Fader told the Associated Press news agency that the trigger for Monday's rally was "heightened fear about military action" against Iran.
"If somehow this got resolved diplomatically," Fader said, "that would definitely take a few dollars off" the price of crude oil.
But traders say that in the short-term the price could rise as high as $75 per barrel.
"Where the top is is pretty hard to say at this point," said New York-based oil broker Tom Bentz.