Iran's seizure of 15 British servicemen last Friday layered renewed geopolitical tensions on top of increasingly robust fundamental forces supporting oil prices.

The confrontation in the world's volatile oil patch threatens to compound an expected march higher for crude futures, already buoyed by strong demand and tightening inventories. Front-month crude prices popped to their highest level of the year on Friday, of $62.65 a barrel, after the incident, settling at $62.28 a barrel, up 59 cents, and the highest since Dec. 22.

Analysts said prices are poised to move higher heading into the spring-summer peak U.S. driving season, even if the episode is resolved quickly, taking their cue from rallying gasoline prices and expectations of an active Atlantic hurricane season, which officially starts June 1.

Iran's ambassador to London was summoned to a "brisk but cordial" meeting with a senior U.K. diplomat who demanded the safe return of the 15 sailors and marines, taken by Iranian forces on what Western officials said was Iraqi waters just outside the disputed Shatt al-Arab waterway. The U.K. Navy personnel, patroling for smugglers on two inflatable boats off the H.M.S. Cornwall, had completed a routine inspection of a merchant ship when they were taken by Iranian forces.

Heightened tensions come as the U.S. bolsters its forces in the Gulf region and the United Nations considers sanctions against Iran for its refusal to halt its nuclear program. Iran maintains it is creating a peaceful nuclear power industry, but the U.S. and its allies claim Iran wants nuclear bombs.

Iran, the second-largest oil producer within OPEC, exports about 2.5 million barrels a day of crude oil to European and Asian customers.