By Daphne Psaledakis and Parisa Hafezi
WASHINGTON/DUBAI, Sept 1 (Reuters) - The U.S. launched new airstrikes on Iranian targets on Tuesday, prompting Iranian retaliation and marking the most serious escalation in weeks in the conflict that has driven up global energy prices and weighed on President Donald Trump's popularity at home.
The strikes followed a weekend exchange of fire -- the first since July -- and Monday strikes on two tankers leaving the Strait of Hormuz, the global oil supply waterway
that Iran has effectively closed to shipping. Global oil prices rose more than $4 a barrel on Tuesday, settling at a five-week high.
Tehran remained defiant, warning that it would prevent oil being exported from the Gulf, despite a threat by Trump to hit Iran "hard" in response to the renewed Iranian strikes, and a warning from U.S. Treasury Secretary Scott Bessent that Washington was about to impose new sanctions.
Five people were killed and 50 wounded at a wedding near Sirik, a coastal area on the Strait of Hormuz, the Iranian Red Crescent reported. The Mehr news agency said a 4-year-old child was among those killed. There was no immediate U.S. reaction to the reports.
The Islamic Revolutionary Guard Corps (IRGC) said in a statement the U.S. attacks would "tighten the lock" on the Strait of Hormuz which carried one of every five barrels of the world's oil before the war. Iranian threats against unauthorized shipping have shut most of the tanker traffic through the strait, driving up oil prices.
"If the enemy wants us not to export oil from the Persian Gulf, no one will be able to export oil," Iranian parliament speaker Mohammad Baqer Qalibaf was quoted as saying by Iranian media.
Neither threats of strikes nor new economic sanctions appear to have materially changed the position of Tehran, which has been under heavy economic sanctions for half a century.
The second round of U.S. strikes in three days followed a month of relative calm in which the U.S. and Iran mostly held their fire while exchanging bellicose statements.
Trump called Tuesday's strikes retaliation for Iranian attempts to place sea mines in the Strait of Hormuz after the U.S. military announced last week it had cleared a strategic shipping lane of Iranian mines, and for Iranian missiles fired at a U.S. military base in Jordan.
Later, sirens sounded anew in Jordan, state television reported. Iran's Islamic Revolutionary Guard Corps said it launched a heavy ballistic missile attack on the U.S. Marine Corps base in Jordan and "killed a large number of U.S. forces." Iran's Fars news agency called it a retaliatory operation that fired missiles and drones.
There were no casualties so far from the Iranian attack on facilities in Jordan, two U.S. officials told Reuters. This was based on initial information and could change as Iranian attacks continued, the officials said.
Jordan's armed forces said its air defense systems dealt with 13 ballistic missiles that entered the kingdom's airspace. The military said 10 missiles were intercepted and destroyed, while three fell in remote areas far from population centers.
Trump had previously warned Iran against retaliation.
"If the failed Nation of Iran retaliates for this very justified attack, they will be hit again at a much harder and higher level, but it will not be the biggest attack of them all, that is waiting in the wings and, when it is over, there will be very little left of the Islamic Republic of Iran!" Trump said in a social media post.
In an interview with Fox News, Trump played down the prospects of another ceasefire. The U.S. and Iran reached a deal in June that quickly fell apart, largely over interpretations of Iranian control of the Strait of Hormuz.
"I think an agreement with them isn't worth the paper it's written on. We gave them a lot of chances," Trump told Fox News.
U.S. SAYS IT HITS REVOLUTIONARY GUARD
The U.S. military's Central Command said the latest wave of U.S. attacks hit IRGC targets.
Iranian media reported multiple strikes, including a U.S. missile attack near the city of Ahvaz and at the civilian Jiroft airport in southeastern Iran, while explosions were heard in the southeastern port of Chabahar, the port city of Bandar Abbas on Strait of Hormuz, and in Asaluyeh, a critical gas hub on the Gulf coast.
Iran's state broadcaster also reported explosions on Iran's Qeshm Island, on the northern side of the strait.
The Fars news agency cited an IRGC spokesperson as saying the U.S. "will regret its new attacks".
The six-month-old conflict had shifted into an economic standoff before the weekend strikes, in which U.S. forces attacked Iran's Larak Island on Sunday and Iran responded by launching missiles at two U.S. air bases in Jordan.
Iranian President Masoud Pezeshkian had said early on Tuesday at a regional summit in Kyrgyzstan that Tehran would reciprocate immediately if Washington honored its commitments under a June Memorandum of Understanding that was intended to halt the conflict.
The MOU declared an end to fighting that has now killed thousands in Iran and Lebanon since U.S. and Israeli strikes began on February 28. But it also deferred many of the most difficult issues and paved the way for a broader 60-day negotiation period — which passed without further agreement.
(Reporting by Parisa Hafez in Dubai, Daphne Psaledakis, Idrees Ali and Jasper Ward in Washington, Bhargav Acharya in Toronto, and Yasmine Ghania, Ahmed Tolba and Muhammad Al Gebaly in Cairo; Writing by Timothy Heritage, Kevin Liffey, Nathan Layne and Daniel Trotta; Editing by Scott Malone, Sanjeev Miglani and Don Durfee)
