The average price of gasoline in the United States has surged to $3.20, its highest level of the year, posting the largest single-day jump in four years as escalating tensions involving Iran shake global energy markets, Business Insider reports.

The national average price for a gallon of regular gas climbed to $3.198, according to AAA. That’s up from $3.109 Tuesday, reflecting a sharp increase in pump prices over the past 24 hours.

The price for a gallon of regular gas has risen from about $2.98 on Feb. 27, the day before the Iran strike, a 22-cent, or 7%, jump.

The spike comes as oil markets react to rising geopolitical tensions in the Middle East following the outbreak of war involving Iran over the weekend.

Recent missile and drone attacks in the region have raised concerns about possible disruptions to global energy supplies.

Particular attention is focused on the Strait of Hormuz, a narrow shipping lane between Iran and Oman through which roughly 20% of the world’s crude oil supply passes. Any threat to shipping through the strait can quickly push oil prices higher.

“Iran has threatened ships traveling through the Strait of Hormuz,” said Patrick De Haan, head of petroleum analysis at GasBuddy, noting that fears of disruptions to the route are rattling energy markets.

Brent crude oil has risen from about $72.48 per barrel on Friday to roughly $83.26, an increase of about $10.78, or nearly 15%.

Oil prices are a major component of gasoline costs, meaning increases in crude typically filter through to consumers within days or weeks.

Seasonal factors may also add pressure to prices at the pump. Gas demand typically rises in the spring as warmer weather arrives and travel picks up.