Explosive-laden Iranian boats appear to have attacked two fuel tankers in Iraqi waters, setting them ablaze and killing one crew member on Wednesday, after projectiles struck four vessels in Gulf waters, said port, maritime ​security and risk firms.

The latest attacks on ships linked to the U.S. and Europe mark an escalation in the conflict between Iran and U.S.-Israeli forces, raising the number of ships struck in the region since fighting began ‌to at least 16.

Shipping in the Gulf and along the narrow Strait of Hormuz, opens new tab, which carries around a fifth of the world’s oil, has come to a near-standstill since the U.S. and Israel began strikes on Iran on February 28, sending global oil prices surging to highs not seen since 2022.

Iran’s Revolutionary Guards have said that if attacks on Iran continued, they would not allow “one litre of oil” to be shipped from the Middle East to the U.S., Israel or their partners.

Trump warned Washington would strike Iran harder if it blocked oil exports, and said oil companies should use the strait because “just about all of (Iran’s) navy is gone.”

The vessels targeted in Wednesday’s late-night attacks in the Gulf near Iraq were the Marshall Islands-flagged Safesea Vishnu and the Malta-flagged Zefyros, which had loaded fuel cargoes in Iraq, two Iraqi port officials said.

Iraq’s State Organization for Marketing of Oil (SOMO) said the Safesea Vishnu was chartered by an Iraqi company contracted with SOMO, and that Zefyros was loaded with condensate products from ⁠Basra Gas Company. Both were attacked in the ship-to-ship loading area within Iraqi territorial waters, SOMO said.

Iraqi oil ports closed

Iraq’s oil ports have completely stopped operations following the assaults, while commercial ports continue to function, Iraq’s state news agency said, citing the head of the state-run General Company for Ports of Iraq (GCPI).

The United Kingdom Maritime Trade Operations (UKMTO) said the crew of one ship had been evacuated and were reported safe.

“A boat belonging to the Iraqi Ports Company rescued 25 crew members from the two vessels, and the fires are still burning on both ships,” Farhan al-Fartousi, GCPI’s director general, told Reuters.

Iraqi rescue teams continue searching for other seafarers.

“We recovered the body of a foreign crew member from the water,” one port security official said.

The Safesea Vishnu’s commercial operator and beneficial operator are Safesea Transport Group and Safesea Group, respectively, according to data from Lloyd’s List Intelligence. Those U.S.-based companies did not immediately respond to requests for comment.