The foreign vessels were reportedly hit by remote-controlled boats laden with explosives while in Iraqi waters. Footage shows one tanker completely set ablaze.

Iraqi oil ports have “completely stopped” operations following the attack, authorities said. The latest attacks sent oil prices climbing on Thursday, with crude hitting over $100 a barrel.

One crew member was killed and 38 others were rescued after the strikes on the Maltese-flagged Zefyros and the Marshallese-flagged Safesea Vishnu near the Iraqi port of Umm Qasr.

Iran’s Revolutionary Guards later officially claimed the attack on the second tanker, branding it “one of the assets of the US terrorist army.”

The explosions came after three cargo vessels were hit by “unknown projectiles” in the Strait of Hormuz, one of the world’s busiest oil shipping lanes, on Wednesday.

Another container ship in the strait was hit on Thursday morning near the United Arab Emirates, the UK maritime agency said.

Tehran has said it would “not allow even a single litre of oil” intended for the US, Israel and their allies to pass through the strait. It has warned crude could soon reach $200 a barrel and that a prolonged war that would “destroy” the world economy.