The U.S. struck Iran's coastal defenses and missile sites on Wednesday after reimposing a naval blockade of its ports, while Iran threatened to shut off more regional energy exports, saying it was engaged in an "existential war" with America.
The latest escalation comes days after a fragile truce collapsed, raising the specter of a return to full-scale war, though analysts generally see that as less likely.
Hostilities have intensified since Iran said late on Saturday it had closed the Strait of Hormuz. Military operations are also keeping ships from transiting the vital artery, which carried about a fifth of global oil and gas shipments before the war. Brent crude oil, the international benchmark, closed at a one-month high of $84.95 a barrel on Wednesday.
U.S. Central Command said the military had attacked coastal defense systems and cruise missile storage and launch sites on Iran's Greater Tunb Island starting around 6 a.m. EDT (1000 GMT), and had completed the wave of strikes within around 90 minutes.
Nine hours later, Central Command reported a second wave of strikes.
"The strikes are targeting Iranian military capabilities used to threaten vessels freely transiting through the Strait of Hormuz, an international waterway vital to global commerce. The U.S. military is holding Iran accountable at the Commander in Chief's direction," Central Command said on X.
Three U.S. officials told Reuters that U.S. strikes aimed at forcing open the strait are also targeting Iranian military capabilities the U.S. would want to destroy before executing more complex operations.
The U.S. military also said it disabled an unladen oil tanker attempting to sail toward Iran's Kharg Island after it ignored multiple warnings, firing Hellfire missiles into the ship's smokestack. Since resuming a naval blockade against Iran on Tuesday, the U.S. has redirected two ships and disabled another, the military said.
Following the latest round of strikes, Iran's Mehr news agency said four locations around the city of Ahvaz came under attack, just inland from the northern end of the Gulf, as did Bandar Abbas, Iran's principal port city on the Strait of Hormuz. In neither case were casualties reported, Mehr said. Iran's Tasnim news agency said explosions were heard in Konarak city, at the southern end of Iran.
U.S. projectiles also hit near Sirik and Qeshm in southern Iran, according to Iran's semi-official media.
Iranian state broadcaster IRIB, however, reported that the U.S. attacks struck near a hospital in Ahvaz that houses a pediatric cancer center, forcing the temporary evacuation of the hospital. Families have come out to the streets around the hospital to care for their children, IRIB said.