World oil prices hit record highs again on Monday.
Crude oil for future delivery cost as much as $53.67 a barrel in New York trading. London's benchmark Brent crude price also hit an all-time record.
Analysts say continuing worries about the supply of oil are driving prices upward. A long list of problems are affecting oil producers, including hurricane damage to U.S. oil facilities, sabotage attacks in Iraq, and labor unrest in Nigeria and Norway.
The shortages come at a time of strong demand for oil from China, the United States, and other nations.