Oil prices jumped Monday after Britain said a racing yacht was seized by Iran in the Persian Gulf and that five U.K. nationals were being held.

Crude quickly climbed $1.23 and settled at $77.28 a barrel on the New York Mercantile Exchange.

The yacht may have strayed inadvertently into Iranian waters when it was stopped last Wednesday, British officials said.

Two years ago 15 British military personnel were seized in the Gulf by Iran. They were charged them with trespassing in its waters, but all were eventually freed.

The jump in prices comes as the gap between what drivers are paying for gasoline in the U.S. compared with a year ago is widening. That gap will likely grow through December, largely because prices were in free fall last year at this time.

Prices at the pump in the U.S. averaged $2.629 a gallon on Monday, 80.4 cents more a gallon than a year ago, according to auto club AAA, Wright Express and Oil Price Information Services. The difference is about $40 per month for a typical motorist.