The average price for a gallon of gasoline jumped 11 cents overnight to about $3.11 in the U.S., according to motor club AAA.
Gas prices were already rising before the U.S. launched strikes on Iran as refiners switch over to summer blends of fuel, but crude futures have risen sharply this week because of the war.
On Tuesday, oil futures soared to levels not seen in more than a year as Iran launched a series of retaliatory attacks, including a drone strike on the U.S. Embassy in Saudi Arabia.
Benchmark U.S. crude jumped 8.6% to $77.36 a barrel.
Brent crude, the international standard, added 6.7% to $81.29 a barrel. Global oil prices jumped to start the week over concerns that the war will clog the global flow of crude.
