Fighting between the US, Israel and Iran is increasingly being felt at sea, with a string of attacks on vessels in the Gulf raising fresh concerns over global energy supplies and the wider economic fallout.

Late on Wednesday, two foreign oil tankers in Iraqi waters were set on fire in what Iran said was an attack carried out using an underwater drone. At least one person was killed and dozens of crew members were rescued.

Iranian state media said the drone strike had hit two tankers in the Gulf. Footage shared with CNN appears to show the moment one of the vessels, the MV Safesea Vishnu, was struck.

The video was filmed from a nearby bulk carrier by Filipino seafarer Dennis Pialago. Further footage recorded by Pialago on Thursday morning showed the tanker badly damaged and leaning in the water, with smoke still rising from the hull even though the flames appeared largely to have died down.

Earlier on Thursday, the UK Maritime Trade Operations centre said a container ship off the coast of the United Arab Emirates had reported being hit by what it described as an unidentified projectile.

Shipping giant Maersk later told CNN that a Liberia-flagged vessel, the Source Blessing, had been involved in an incident in the Gulf during the early hours of Thursday local time. A fire broke out on board but was later brought under control, and no crew members were reported injured. Maersk said the ship was operating on its behalf under a time-charter arrangement.

On Wednesday, UKMTO also received reports that three other vessels near the Strait of Hormuz had been struck by projectiles. One of the incidents caused a fire on board, prompting the evacuation of some crew.

Among the ships hit that day was a Thai bulk carrier. Thailand’s transport ministry said an explosion at the stern caused a blaze in the engine room.