The US launched a second night of strikes on Iran on Wednesday, with President Donald Trump calling them "retribution".
US Central Command said in a post on X that, at Mr Trump's direction, it had started conducting more strikes to "further degrade" Iran's ability to threaten freedom of navigation in the Strait of Hormuz.
"The United States is holding Iran accountable for recent unjustified aggression against commercial shipping and civilian crews freely navigating a vital international waterway," it said.
The latest strikes come after Iran was accused of attacking commercial ships in the Strait of Hormuz. After the first night of strikes, Iran attacked sites in Bahrain and Kuwait.
On Wednesday, Iranian media reported explosions in Bandar Abbas and Sirik in the country's south, among other areas.
Mr Trump warned of worse to come. "This is in retribution for yesterday’s bombing of ships by Iran," he wrote on Truth Social. "If it happens again, it will get much worse."
His post was accompanied by reposts of what appeared to be images and videos of the aftermath of strikes.
En route home from the Nato summit, Mr Trump said Iran "called a little while ago" and wanted to make a deal, but he said that he does not trust them to honour one.
Earlier, Mr Trump had warned the strikes could occur again. "We'll probably hit them hard again tonight ... they're cuckoo," he said as he attended a Nato summit in Turkey.
An Iranian adviser to the country’s supreme leader said that Tehran would deliver an “immediate response” to the US after Mr Trump's threats.
Ali Velayati repeated Iran’s warning that the region “is not a place for political gambling by small entities".
Islamic Revolutionary Guard Corps Maj Gen Mohsen Rezaei said in a post on X: "The aggressor enemy and his accomplices will be severely punished."
Before the latest attacks, Iranian media quoted a security source as saying Iran would strike "enemy" targets at a ratio of at least two to one and close the Strait of Hormuz.
The escalation has cast further doubt on the durability of an uneasy ceasefire that has been in place for three months. The two sides are trying to negotiate a long-term peace deal.
Peace talks are on the brink of collapse, and Mr Trump has declared the interim ceasefire "over".
