US Central Command (Centcom) said the attacks were intended to "further degrade Iranian military capabilities", before saying it had boarded a vessel as part of its blockade of Iranian ports.
State media and provincial authorities reported that the US had hit civilian infrastructure, including bridges, a train station and an airport. BBC Verify has confirmed an attack on one bridge to the west of Bandar Abbas in Hormozgan province.
Iran's Revolutionary Guard Corps (IRGC) says it has retaliated by striking US maritime surveillance radar sites in Oman as well as targets in Kuwait and Bahrain. It also claims to have attacked a US special operations command centre in Syria.
The IRGC said the surprise attack at al-Tanf in Syria, near the border with Jordan, was in retaliation for the killing of Iranian soldiers two days ago. Neither Syria nor the US have commented on the claim.
Kuwaiti authorities said the Iranian strikes hit power generation and water desalination stations, causing damage to facilities, a fire and the disruption of a large number of electricity generation units.
Jordan's military said it shot down three Iranian missiles with no casualties or damage reported.The IRGC claimed it struck US fighter jets stationed in the Gulf country, according to state TV.
Meanwhile in Iraqi Kurdistan, eight people were killed and several injured in the city of Sulaymaniyah in the early morning, according to Kurdish news agency Rudaw and Agence France Press news agency. Kurdish forces blamed the attack on Iran.
Separately, Kurdish forces said eight drones were also shot down over the city of Erbil, with no casualties reported.
As attacks escalate, the Strait of Hormuz - a critical waterway off Iran's coast that Tehran effectively blocked in response to US-Israeli strikes - has remained shut.That has impacted the flow of oil from the region and the head of the International Energy Agency, Fatih Birol, says he has concerns about global energy supplies.
"We should be worried, and I am worried, if the situation does not improve in the next few weeks," Birol said on Thursday night.
On Friday the Chinese and Pakistani foreign ministers called for the US and Iran to stop fighting and resume negotiations.
The US launched strikes for the sixth night in a row, as fighting over control of the Strait of Hormuz continues. The US overnight strikes also hit close to the island of Qeshm as well as in the southern coastal cities of Bandar Abbas and Bushehr - the site of a nuclear power plant
Centcom did not mention bridges in its list of the "dozens of Iranian military targets" it hit in the latest round of strikes. It said jets, drones and ships had attacked "coastal surveillance and air defense sites, military logistics infrastructure, and maritime capabilities". The BBC has asked Centcom for comment.
Iranian state media and local officials said Washington targeted Iranshahr Airport in southeastern Iran, a railway station and six bridges in the Hormozgan province.
Seven people were killed in the strikes, provincial authorities in Hormozgan said.
BBC Verify and BBC Persian have verified footage of damage to one of the bridges, Gariveh Bridge, which connects the southern cities of Bandar Abbas, Bandar Khamir and Lar.Overnight video captured the bridge with a ball of flames on top of it, as cars stopped behind the fire.
Morning images show a crumbled stretch of road with rubble around the broken bridge.
A damaged portion of the bridge in the aftermath of the overnight strike in Bandar Khamir, Hormozgan province.Iranian outlets reported power cuts in Hormozgan province due to damage to electricity infrastructure caused by the US attacks.
There were also multiple strikes in the provinces of Khuzestan, Bushehr, Hormozgan and Sistan-Baluchestan, along Iran's southern coast, according to reports last night from Iranian outlets.Earlier this week US President Donald Trump threatened to strike Iran's bridges and power plants.
After Trump said in April that the US would bomb civilian infrastructure in Iran, including bridges and power plants, UN human rights chief Volker Türk said "deliberately attacking civilians and civilian infrastructure is a war crime".
At least 38 people have been killed and more than 400 injured in the country since fighting resumed with the US, Iran's health ministry said.
Reuters Smoke rises following a strike at an unknown location during what the U.S. military says is its latest wave of strikes on IranReuters. Smoke rises after what the US military says is its latest wave of strikes on Iran
Centcom also said marines had boarded an oil tanker in the Gulf of Oman as part of the renewed US blockade of Iran's ports that began on Tuesday night.
It added it had "redirected 3 commercial vessels trying to run the blockade".
On Friday the United Kingdom Maritime Trade Operations reported a tanker had been hit by an unknown projectile on Thursday while sailing near Khasab in Oman. All crew members were reported safe.
According to Centcom, US forces disabled nine ships and redirected more than 140 under its previous blockade of Iranian ports between 13 April to 18 June.The renewed hostilities have put further strain on the deal to end the war.
White House press secretary Karoline Leavitt said on Thursday that while Trump was "always open to diplomacy" and Iran was still open to making a deal, "the president is not going to allow [Iran] to fire on ships in the strait without paying a consequence for that."
Iran's top negotiator, Mohammad Bagher Ghalibaf, said on Wednesday that Tehran had "no reason" to abide by any agreement that did not benefit the country, as its national security depended on "Iranian arrangements" in the strait.
Meanwhile, Trump on Wednesday praised Iran's "gesture of goodwill" for freeing Dena Karari, a US citizen who he said had been "wrongfully detained" in December 2024, after her lawyer said she was coming back to the US.However Iran's judiciary said on Thursday no US prisoner had been released or exchanged.