Global oil prices surged past $100 a barrel on Thursday for the first time since May, driven by escalating conflict involving Iran and recent attacks on shipping.

The benchmark Brent crude futures reached $100.60 per barrel in afternoon trading, marking a significant increase of approximately 29% over the past month. This surge marks the highest oil price level seen since late May, reflecting growing concerns over global energy supply stability.

The price jump follows claims by Houthi militants in Yemen of striking two Saudi tankers in the Red Sea. This incident occurred alongside continued strikes between the United States and Iran, raising fears of a further worsening of an oil shock that has already been historically significant.

Major stock markets reacted negatively to the rising energy costs, with the Dow Jones Industrial Average falling 525 points, or 1%, and the S&P 500 declining 1.2%. The tech-heavy Nasdaq experienced a more substantial drop of 2.2%.

The recent escalation of fighting between the U.S. and Iran has jeopardized a preliminary agreement that had previously led to a brief dip in oil prices to their lowest point since the conflict's outbreak in late February. Shipping traffic through the Strait of Hormuz, a crucial artery for approximately one-fifth of global oil supply, has seen a sharp decline in recent weeks.

Adding to the supply concerns, the U.S. reimposed its naval blockade of the Strait of Hormuz last week, reversing a key commitment from the prior agreement. This move came after Iran reportedly fired upon oil tankers in the strategic waterway. Saudi Arabia, which relies on an alternative pipeline route to the Red Sea, now faces potential disruptions to its crude transportation following the reported Houthi attacks.

The average price of gasoline in the United States has also climbed, now standing at $4.09 per gallon according to AAA, after surpassing the $4 mark earlier this week. The price of crude oil significantly influences the cost of gasoline at the pump.

Uncertainty remains regarding the future trajectory of oil prices and the broader economic implications, as geopolitical tensions continue to affect critical global trade routes and energy markets.