Fears of renewed escalation have gripped the Middle East after the United States and Iran exchanged their biggest barrage since July, with Washington striking Iran's southern coast and Tehran firing at US bases across the region.
With the US threatening further strikes overnight, Iran accused Washington of hitting a wedding party, killing four people and wounding dozens. Its health minister later said 18 people had been killed and 108 injured in the latest wave of US strikes.
The US military said it struck air defences, radar systems, maritime assets, mine-laying capabilities and communications sites on Tuesday. Iran reported hits on multiple targets near the Strait of Hormuz.
The flare-up threatens to deepen a conflict that has dragged on since the US launched strikes on Iran in February, disrupting global energy supplies and drawing opposition from a majority of Americans ahead of November's congressional elections.
President Donald Trump said the US hit Iran "very hard" and that Iran only responded with a "love tap".
"It was a very heavy attack last night, and we're prepared to do another one any time we want," Trump told reporters at the White House on Wednesday.
Iran struck what it said were US assets in Bahrain, Jordan, Kuwait and Iraq, and said its aim was now to drive US forces from the vast network of military bases they have maintained for decades across the Middle East.
"American evil in the region will be met with heavier, more widespread, and devastating responses, and any country that cooperates with the aggressive American army must accept its dangerous consequences," Iran's military command said.
Iran said it killed US forces in Jordan and at a base in northern Iraq, but US officials told Reuters there had not been any casualties, according to initial assessments.
In Kuwait, Iran said it had carried out a missile and drone attack on the US Ali Al Salem air base and on a residential complex used by a US commander. Kuwait’s fire service said it put out a blaze at a residential complex hit by a drone.
Qatar, home of the largest US air base in the Gulf, said it held Iran responsible for attacks and their repercussions. Bahrain, which houses the regional headquarters of the US Navy, said Iranian drones were intercepted and destroyed.
Iran also said two tankers had been struck by mines while being steered through the Strait of Hormuz by US personnel.
Washington says despite Iranian attacks it is guiding ships through the strait. Energy Secretary Chris Wright said more than 17 million barrels of oil exited on Monday.
Trump repeated his assertion that the strait, which handled 20 per cent of global oil and liquefied natural gas shipments before the war, was open to shipping.
Iran said four people including a four-year-old were killed while celebrating a wedding at a home in Sirik. Iranian media said as many as 68 people were wounded there, and released images of injured children in hospital.
Reuters was unable to independently verify the incident.
The exchange of fire was the worst since July, when Trump abruptly halted two weeks of intense bombing of Iran after warnings from his military brass that they were using up munitions and running out of meaningful targets.
Trump has yet to achieve the aims he set when launching "Operation Epic Fury" in February — to end Iran's nuclear program, deprive it of the ability to strike its neighbours and create conditions for Iranians to topple their rulers.
But the US has seriously degraded Iran's conventional military forces and taken a toll on Iran's already weakening economy, US officials say.
Sources have told Reuters Trump aides are trying to keep the war quiet for now to avert a defeat in the midterm elections in November. Polls show Americans oppose the war by more than a two-to-one margin.
