World crude oil prices surged above $73 on Thursday amid worries over Nigeria and Iran.
New York's main contract, light sweet crude for delivery in June, added $1.19 to close at $73.32 a barrel.
On London's ICE Futures exchange, the price of Brent North Sea crude for June delivery was up 99 cents to settle at 73.43 dollars a barrel.
Three foreign workers were kidnapped on Thursday in Port Harcourt, Nigeria., after the murder of an American oil industry executive in the same city.
About one-fourth of Nigeria's daily output is still shut after a series of militant attacks. Nigeria is Africa's leading oil producer and the fifth-biggest source of U.S. oil imports.
