DUBAI, United Arab Emirates -- Sailors involved in transferring fuel oil from an Iraqi tanker in the Persian Gulf to another vessel owned by a shipping company traded in the U.S. discovered a "suspicious object" they fear could be a mine, authorities said Thursday.
The discovery was made as tensions remain heightened between Iran and the U.S. in the waning days of President Donald Trump's administration.
Already, America has conducted B-52 bomber flyovers and sent a nuclear submarine into the Persian Gulf over what Trump officials describe as the possibility of an Iranian attack on the one-year anniversary of the U.S. drones strike in Baghdad that killed a top Iranian general.
Two private security firms said sailors feared they found a limpet mine on the MT Pola, a Liberian-flagged tanker that was receiving assistance Thursday in the Persian Gulf off Basra.
A limpet mine is a type of naval mine that attaches to the side of a ship, usually by a diver-member of special forces. It later explodes, and can significantly damage a vessel.
The two firms, Ambrey Intelligence and Dryad Global, say investigations are ongoing.
The United Kingdom Marine Trade Operations, an organization under Britain's navy, said on its website that an "unknown object" had been attached to a ship's hull in the vicinity of Iraq's Khor Al-Zubair Port, without providing further information.
The U.S. Navy's 5th Fleet, which patrols the Mideast, was monitoring the incident, said spokeswoman Cmdr. Rebecca Rebarich. Iraqi officials did not immediately comment on the incident.
The Pola, along with another tanker, serves as floating fuel oil storage of Iraq's state oil agency, said Sudharsan Sarathy, a senior oil analyst at the data-analysis firm Refinitiv.
Smaller vessels carry the fuel oil to the ship, which then conducts ship-to-ship transfers in the Persian Gulf to clients.
Sarathy said the Pola was conducting a ship-to-ship transfer with the MT Nordic Freedom, a Bermuda-flagged tanker. Dryad Global posted a satellite photo that it said showed the Pola and the Nordic Freedom.
The owners of the Nordic Freedom, the company Nordic American Tankers, could not be immediately reached. Stock in the firm traded slightly down early Thursday on the New York Stock Exchange at just under $3 a share.
In 2019, the U.S. blamed Iran for a series of limpet mine attacks on oil tankers near the Strait of Hormuz, the narrow mouth of the Persian Gulf through which 20% of all the world's oil passes. Iran denies being involved.
The tankers involved in Thursday's incident were sitting just offshore from the border of Iraq and Iran near the mouth of the Euphrates and Tigris rivers in the Shatt al-Arab.
Iran has been closely allied to Iraq since the 2003 U.S.-led invasion that toppled dictator Saddam Hussein, while also arming and aiding militia groups in the country.
Iranian Foreign Minister Mohammad Javad Zarif on Twitter earlier Thursday criticized Trump for wasting "billions to fly B52s & send armadas to OUR region."
"Intelligence from Iraq indicate plot to FABRICATE pretext for war," Zarif wrote. "Iran doesn't seek war but will OPENLY & DIRECTLY defend its people, security & vital interests."
Separately, the Pentagon has decided to send home the only Navy aircraft carrier operating in the Middle East, a move that will reduce American firepower in the region.
The decision was announced Thursday by the acting secretary of defense, Christopher Miller.
Sending the aircraft carrier, the USS Nimitz, home to the U.S. West Coast would seem at odds with the idea that a show of force is needed to deter Iran. This might reflect a split within the defense establishment on whether Iran poses a heightened threat to strike in the waning days of the Trump administration.
In announcing the decision to send the Nimitz home, Miller made no mention of Iran.
Information for this article was contributed by Isabel DeBre, Zeina Karam and Robert Burns of The Associated Press.