Crude oil prices rose above 59 U.S. dollars a barrel Friday on unrest in Nigeria, the top oil producer in Africa.
The U.S. consulate in Lagos warned that militants in Nigeria are planning to expand their attacks.
"Possible targets could include expatriate personnel, Western businesses or facilities and locales visited by tourists and foreigners in other regions of Nigeria," the consulate said. "Attacks and kidnappings may become more violent than in recent months."
Light, sweet crude for March delivery rose 1.40 dollars to 59.39 a barrel on the New York Mercantile Exchange.
Brent crude oil for April rose 1.35 dollars, or 2.3 percent, to58.95 a barrel on the London-based ICE Futures exchange.
