Iran has fired cruise missiles and drones, and has launched small boats to target U.S.-flagged ships in the Strait of Hormuz, but none were struck, according to the commander of U.S. Central Command.

The U.S. used attack helicopters to blow up the small boats and intercept the drones, according to Adm. Brad Cooper. He said in a call Monday that U.S. Navy ships were protecting U.S. commercial vessels transiting the strait, as part of President Donald Trump’s new mission to guide stranded vessels through the critical waterway.

Cooper would not address whether this meant the U.S.-Iran ceasefire that began April 8 was now over. Iran and the U.S. each denied there had been any damage done to their vessels, as both nations appeared to play down the military activity in the Strait of Hormuz.

“I wouldn’t go into details of the whether the ceasefire is over or not,” Cooper said. “I think the key thing is for us is we’re merely there as a defensive force and enforce, to give a very thick layer of defense to commercial shipping to allow them to proceed out of the Arabian Gulf.”

But Cooper said Iran was “initiating aggressive behavior.”

The regime launched “multiple cruise missiles” at U.S.-flagged ships in the Strait, and at the U.S. Navy ships that were protecting the commercial vessels, Cooper said.

Iran claimed to have struck an American warship, but Central Command said no ship was hit. Iran also denied the U.S. sank any of its boats, according to Islamic Republic of Iran Broadcasting.

The ministry of defense of the United Arab Emirates said Monday in a post on X that they had “engaged” 12 ballistic missiles, 3 cruise missiles and 4 drones fired from Iran, which resulted in 3 mild injuries.

Over the weekend, the United Arab Emirates said Iran had launched missiles at the country for the first time since a ceasefire was declared a month ago. Iranian state media reported it had no plans to target the UAE.

And the South Korean government also said an explosion and fire had occurred on a South Korean-operated cargo ship. In a statement, the country’s foreign ministry said the ship was Panama-flagged and called it a “possible attack.”

There were 24 crew members on board, the foreign ministry said — six South Koreans and 18 from other countries — and no casualties were reported.

The vessel was at anchor near the UAE in the strait when the explosion happened, it said.

Speaking on Truth Social Monday, Trump said Iran had “taken some shots” at other countries, and he encouraged South Korea “to come and join the mission!”

In a separate post Monday, Trump didn’t acknowledge Iran had targeted any U.S.-flagged vessels.

“We’ve shot down seven small Boats or, as they like to call them, “fast” Boats. It’s all they have left. Other than the South Korean Ship, there has been, at this moment, no damage going through the Strait,” he wrote.

And in an interview with Fox News, Trump warned that if Iran attacks any American vessels they will be “blown off the face of the Earth.”

Asked if the ceasefire with Iran is over and whether a U.S. attack is imminent in an interview on the “The Hugh Hewitt Show,” Trump replied, “Well, I can’t tell you that.”

Trump announced Sunday that beginning on Monday the U.S. military would help free ships that have been “locked up” and unable to pass through the key trade route amid the maritime standoff between Tehran and Washington.

Cooper said that multiple Navy-guided missile destroyers are operating in the Gulf, helping commercial shipping and providing air defenses with their helicopters.

Iran signaled an aggressive response to this latest bid to break its stranglehold over the strait, which has left global shipping at an effective standstill and sent energy prices spiraling.

Tehran issued a new map and a flurry of statements that sought to reassert its control. Early Monday, it claimed to have stopped U.S. destroyers from entering the strait.

After the U.S. warships ignored several radio warnings, Iran fired cruise missiles, rockets and combat drones near them, army public relations said in a statement carried by the semi-official Tasnim news agency.

Vehicles drive past a billboard with graphic showing Strait of Hormuz and sewn lips of President Trump in Tehran, Iran on May 2, 2026.  (Vahid Salemi / AP)

A billboard in Tehran, Iran, appears to show the sewn lips of President Donald Trump covered in a ribbon shaped to represent the Strait of Hormuz. (Vahid Salemi / AP)

(Vahid Salemi)

Two U.S.-flagged merchant vessels had successfully transited through the strait “as a first step” in Trump’s new mission, Central Command said.

The U.S. said that 15,000 service members, guided-missile destroyers, over 100 land and sea-based aircraft and multidomain unmanned platforms are involved in the new operation.

Trump announced the effort in a lengthy TruthSocial post Sunday. The U.S. would guide ships from countries not involved in the Middle East crisis safely out of the strait, “so that they can freely and ably get on with their business,” he said.

The map shows a line between Iran's Qeshm island and the United Arab Emirates' Umm al Quwain emirate. In the east, the area stops at a line between Iran's Mount Mobarak and the UAE's Fujairah. (via FARS)

The map shows a line between Iran’s Qeshm island and the United Arab Emirates’ Umm al Quwain emirate. In the east, the area stops at a line between Iran’s Mount Mobarak and the UAE’s Fujairah. (via FARS)

(via FARS)

It said vessels should consider routing via Oman territorial waters as usual routes should be considered “extremely hazardous due the presence of mines that have not been fully surveyed and mitigated.”

Iran’s navy shared a new map of what it said was the area of the strait under its control, though it was not clear whether this represented any change.

Passage must be carried out in coordination with Tehran, its military command cautioned. “We warn that any foreign armed force, especially the aggressive military of America, should they intend to approach or enter the Strait of Hormuz, will be subjected to attack,” Major General Pilot Ali Abdollahi said in a statement carried by state TV channel IRIB.

Maritime movements that are inconsistent with Tehran’s “declared principles” will face serious risks, said Hossein Mohebbi, a spokesman for Iran’s Revolutionary Guard.

Hundreds of ships and thousands of crew members have been stranded in the area since Iran launched attacks and threatened shipping in the wake of the joint U.S.-Israeli assault more than two months ago.

Many of them are running low on food and other necessities, Trump said, calling his move to free them up a “humanitarian gesture” by the U.S.

Two other ships were attacked in the strait this weekend, the British military’s United Kingdom Maritime Trade Operations Center said.

Ships and boats in the Strait of Hormuz, Musandam (Reuters)

Ships and boats in the Strait of Hormuz near Musandam, Oman, on Friday. (Reuters)

(Reuters)

Trump’s announcement was done without industry coordination, leaving shipping companies scrambling for details, industry figures said.

“The overall security situation for the shipping industry is currently unchanged,” Jakob Larsen, chief safety and security officer with shipping association BIMCO, told NBC News in an email Monday.

He questioned whether Trump’s plan was sustainable longer term and said it risked “hostilities breaking out again.”

With peace talks stalled, energy prices have been rising.

Oil prices climbed slightly overnight, and the international benchmark Brent crude jumped further to above $110 a barrel after the dueling claims of the Iranian and U.S. Navy. The national average gas price in the U.S. continued to rise, hitting $4.46.

Neither side has offered much optimism about a deal to end the war, but Tehran said Monday it was reviewing the latest U.S. counterproposal.