The UK Maritime Trade Operations agency said it had received reports of several merchant vessels in the northern Gulf and the Gulf of Oman being “subject to disabling fire as part of ongoing military activity in the region”.

It also reported that one vessel 24 nautical miles (45km) north-west of Port Rashid, in the United Arab Emirates, was seen “listing while at anchor, possibly indicating water ingress following an attack from an unknown projectile”.

Iraqi authorities said they extinguished a fire on a Panama-flagged tanker, New Andros, that was carrying two million barrels of fuel oil when it was hit by a drone in the Gulf.

On Wednesday afternoon, IRGC spokesman Hossein Mohebi told Iranian state TV that it would soon announce the co-ordinates for a new “prohibited zone” covering “part of the Sea of Oman and another part of the Arabian Sea, along the route that can lead to the Strait of Hormuz”.

“If a vessel enters that area without co-ordination, it will be subject to our sanctions,” he said.

When asked by reporters about the latest tit-for-tat strikes, US Secretary of State Marco Rubio said on Tuesday that the situation was “pretty straightforward”.

“Iran continues to try to hit US naval ships. And, for every time they do that or try to do that, they’re going to lose tankers. And I think you’ll see that again today,” Rubio told reporters during a trip to Colombia.

The US strikes on Tuesday came hours after Iran’s Navy said it had seized an uncrewed US submarine in the Strait of Hormuz.

US Navy Capt Tim Hawkins, a spokesperson for Centcom, said an “underwater drone operated by US forces malfunctioned more than a day ago” and that it had been used to survey regional waters.

Saudi Arabia and the Houthis, an Iran-backed group that controls much of north-western Yemen, have also been exchanging fire.

Following a wave of air strikes on Sunday and Monday, the Houthis accused Saudi Arabia of bombing a prison in Hazm. The group’s military spokesman Yahya Sarea said on Wednesday that the bodies of 23 civilians had so far been pulled from the rubble.

On Tuesday, the Houthis launched dozens of drones and missiles at civilian and economic sites in the southern Saudi cities of Abha, Khamis Mushait, Jazan and Najran, injuring 73 civilians, according to Saudi authorities.

The attacks caused fires at oil facilities that led to a temporary halt in operations, they said.

On Wednesday, the Houthis reported more than 50 Saudi air strikes across territory they control in the provinces of Marib, Jawf, Taiz, Hudaydah, Saada and Bayda.

There was no immediate comment from the Saudi military.

There has also been heavy fighting on Yemen’s south-western coast since Thursday, when the Houthis launched an offensive against Saudi-backed Yemeni pro-government forces in a bid to take control of the Bab al-Mandab Strait, which connects the Red Sea to the Gulf of Aden.

More than 500 people have reportedly been killed and almost 20,000 displaced.