The fragile US-Iran ceasefire is under strain again as the warring sides traded shots in the Strait of Hormuz.

Tensions reignited as the US claimed it “shot down” seven Iranian small boats.

US Central Command accused Iran of launching multiple cruise missiles, drones and small boats at US Navy ships and commercial vessels.

Iran said its navy had fired warning shots at US destroyers.

In a Fox News interview, Trump also warned that Iran’s forces would be “blown off the face of the Earth” if they tried to target US vessels involved in his new Project Freedom in the strait.

Trump said Project Freedom — aiding international ships and their crews that have been “locked up” in the strait — would begin on Monday (local time).

“We have told these Countries that we will guide their Ships safely out of these restricted Waterways, so that they can freely and ably get on with their business,” Trump said in a post on his ‌Truth Social site on Sunday.

US Central Command said it would support the effort with 15,000 US military personnel, more than 100 land and sea-based aircraft along with warships and drones.

But Iran’s state-run IRNA news agency called Trump’s announcement part of his “delirium”.

Ebrahim Azizi, head of the national security commission of Iran’s parliament, said any interference in the strait would be seen as a ceasefire violation.

Meanwhile, the United Arab Emirates has been drawn back into the conflict when a suspected Iranian drone attack sparked a fire in a major oil industry zone.

The Gulf state also intercepted three Iranian missiles over ‌its waters and a fourth crashed into the sea.

The drone attacks shattered a period of relative calm in the UAE since a ⁠Pakistani-mediated ceasefire between the US and Iran took effect ‌on ​April 8, pausing more than two months of intense fighting in the Gulf region.

During the ​period of ‌intense conflict, the UAE said it had intercepted and destroyed thousands of drones and ​missiles.

UAE authorities on Monday issued mobile phone alerts in Dubai and Abu Dhabi warning of the possibility of missile attacks.

Iran’s Revolutionary Guards Navy issued a map it said showed an ​expansion of areas under Iranian control near the Strait of Hormuz, encompassing the UAE ports of Fujairah and Khorfakkan as well as the coast of the Umm Al Quwain emirate, Iranian news agencies reported.

Monday’s strike was not the first time Fujairah’s ​energy infrastructure ​had been in the crosshairs.

​A drone attack on March 14 had previously hit ‌the Port of Fujairah, triggering fires and the suspension of some oil-loading operations.

Fujairah has been key to UAE oil exports during the Iran war as it sits at the end of the Abu Dhabi Crude Oil Pipeline, which carries crude from inland fields to ​the Gulf of Oman, bypassing the Strait of Hormuz.

This has allowed the UAE to ​continue shipping oil to ⁠global markets even as the waterway remained under threat.

US Admiral Brad Cooper, the head of Central Command, said on Monday that the US military ‌destroyed six Iranian small boats ‌and intercepted Iranian cruise missiles ‌and drones as the US launches an operation to free ‌up shipping ‌through ⁠the Strait of ​Hormuz.

Cooper said he “strongly ⁠advised” ‌Iranian ​forces to remain clear of ​US military ‌assets as it launches ​the operation.

He said the US blockade of ​Iran, ​which ​prevents ships from ‌going to Iran or departing Iranian territory, also remained in effect and was exceeding ​expectations.

–with AAP