The increasingly tense standoff between Iran and the UK over the fate of 15 British sailors and marines captured by Iran has helped drive crude oil prices to a six-month high.

Traders sent the price of crude oil up by 3 percent, to $66.03 a barrel in New York yesterday, after Iran put off a previously announced plan to release, Seaman Faye Turney, the sole woman being held hostage. The price of gasoline for April delivery in New York commodity markets jumped 7.83 cents, or 3.8 percent, to $2.1355 a gallon, the highest closing price since last Summer.

Oil traders worried that the conflict could disrupt Iran’s oil exports or shipments through the Strait of Hormuz. Edward Morse, a managing director and chief energy economist of Lehman Brothers, said “speculative investments” were pushing up the price “because of the 17.5 million barrels a day of oil that goes through the Strait of Hormuz.”