Two tankers were struck in Iraqi waters south of Basra on Wednesday, with a fire confirmed on board one of the vessels, while a separate cargo ship was hit hours later off the United Arab Emirates (UAE), in the latest escalation of security risks in the Gulf.

The British military’s United Kingdom Maritime Trade Operations (UKMTO) said the first incident took place about five nautical miles south of Al Basrah, after the chief security officer of one of the vessels reported that a fire had broken out following an attack. It said the crew had been safely evacuated.

The tankers were believed to have been involved in a ship-to-ship transfer operation at the time.

TankerTrackers.com said the vessels involved were the Greek-owned oil and chemical tanker Zefyros and the US-owned Safesea Vishnu.

According to Pole Star Global’s PurpleTrac, the Malta-flagged Zefyros and the Marshall Islands-registered Safesea Vishnu were shown alongside each other on AIS tracking data.

Noam Raydan, who tracks ship attacks in the Middle East, said the Zefyros was carrying condensates for Basrah Gas Company and was due to offload before loading another 30,000 tonnes of naphtha, according to Iraq’s State Oil Marketing Organisation.

Iraqi state television reported that the attack set the ships ablaze, while the head of the Iraqi Ports Authority, Farhan al-Fartushi, said one sailor had died and search and rescue operations were under way for a missing crew member.

According to the same reports, 38 crew members were rescued by forces operating in the area, while both ships were still burning in the early hours after the incident.

UKMTO separately reported that a cargo ship was struck about 35 nautical miles north of Jebel Ali in the United Arab Emirates, causing a fire on board. It said the crew were safe.

The twin incidents off Iraq, together with other reported strikes in the wider Gulf over the past 24 hours, have added to concerns over the safety of commercial shipping through one of the world’s most important routes for oil and goods.