Oil prices were jumping higher after the U.S. military intercepted Iranian ballistic missiles aimed at American forces in Jordan.

Shortly after the attack, the U.S. and Saudi Arabia launched strikes in Iraq against Iran-backed groups that the Islamic Revolutionary Guard Corps previously directed to attack American troops and Saudi energy infrastructure.

The escalation in hostilities hit market hopes that the vital Strait of Hormuz waterway would reopen. More than a quarter of the world's crude usually passes through the shipping channel and tanker traffic remains essentially halted.

Brent crude, the global benchmark, rose 3.5% to $84.97 a barrel. West Texas Intermediate futures, the U.S. standard, were up 3.7% at $82.16.

"These developments throw cold water on the idea of a swift de-escalation in the Persian Gulf," analysts at ING said. "Clearly, with Saudi oil infrastructure increasingly targeted, the risk of more prolonged supply disruptions grows."

The shares of oil majors were also rising after the military escalation in the Gulf region. ExxonMobil stock was up 1.6% at $155.43 in Wednesday's premarket. Chevron was rising 1.4% at $190.16, while Occidental Petroleum was up 2% at $55.