Iran said Monday it attacked US military targets in Jordan in retaliation for the first American strikes on its territory in a month, marking a fresh flare-up in the six-month war.
Tehran's powerful Revolutionary Guards said they struck two US military air bases with ballistic missiles in Washington-allied Jordan, causing "heavy damage."
Jordan's army said it had intercepted eight missiles, without stating their origin.
The strikes came after the United States said Sunday it had attacked Iranian rocket launchers on a small island in the Strait of Hormuz.
Washington said its attacks were aimed at preventing Iran from launching more sea mines into the strait, days after it announced it had completed clearing explosives from the strategic waterway.
"US forces took limited, precise action against IRGC (Iran's Revolutionary Guards') minelaying forces posing an imminent threat in the Strait of Hormuz," the US Central Command wrote on X.
The Guards said the US strikes resulted in "casualties" and that their subsequent attack on Jordan was "in response to the US-Zionist aerial aggression."
The exchange of fire came shortly after the US-Iran war hit the six-month mark, and at a time when hostilities had been subsiding.
In recent weeks, the administration of US President Donald Trump has prioritized "economic warfare" over military strikes on Iran.
Tehran has effectively blocked the Strait of Hormuz, a strategic sea lane through which one-fifth of the world's oil passed before the United States and Israel triggered hostilities with strikes on Iran on February 28.
"Last week, CENTCOM completed clearing sea mines from the strait's international shipping routes," said Navy Captain Tim Hawkins, a spokesman for US Central Command.
"US forces are monitoring the area closely and remain prepared to protect the free flow of commerce through this essential waterway," he said.
- Unpopular war -
Diplomatic efforts, spearheaded by mediators including Pakistan and Qatar, have tried for months to bring an end to the war.
While a ceasefire was agreed in April and a memorandum of understanding towards a final peace deal was signed in June, no agreement has been forthcoming, and Washington has since declared "economic warfare" against Tehran.
A US naval counterblockade of Iranian ports is squeezing petrol supplies in Iran during a shortfall in domestic production, as the US ramps up the pressure.
The April ceasefire put an end to the most intense fighting, but sporadic attacks, mainly around the Strait of Hormuz, have dimmed the prospects of a final peace agreement.
The last US strike on Iran prior to Sunday's came on July 29 in response to "an attempted surprise attack on US forces" in the region, the US military said. Earlier in July, CENTCOM attacked Iran for 13 consecutive nights.
Throughout the war, Iran has fought back by striking US facilities and allies in the Gulf region, hitting targets in Kuwait, Oman, Saudi Arabia and the United Arab Emirates, among others.
Its closure of the Strait of Hormuz has caused pain around the world in the form of price hikes and shortages of fertilizer and energy.
Oil prices rose after news of the US strikes on Iran. A barrel of North Sea Brent crude, the international benchmark, climbed back above the symbolic $90 threshold. West Texas Intermediate rose to more than $85.
The Iran war is deeply unpopular with the US public, with midterm elections looming in November that could overturn Republican control of Congress.
In a statement on Friday, US Senator Jack Reed criticized Trump over the war.
"Six months later, not a single objective has been achieved," said Reed, the top Democrat on the Senate Armed Services Committee.
"Indeed, he has weakened our position in the Middle East and the world significantly."