US confiscates Iran oil cargo on tanker amid Tehran tensions

The U.S. confiscated Iranian oil on a tanker at sea in recent days in a sanctions enforcement operation, three sources said, and days later Iran seized another oil-laden tanker in retaliation, according to a maritime security firm.

As oil markets remain jittery, the cargo seizure is the latest escalation between Washington and Tehran after years of sanctions pressure by the U.S. over Iran's nuclear program. Iran does not recognise the sanctions, and its oil exports have been rising.

Tehran says its nuclear program is for civilian purposes while Washington suspects Iran wants to develop a nuclear bomb.

Maritime security company Ambrey said the U.S. confiscation took place at least five days before Iran's action on Thursday. "Ambrey has assessed the seizure by the Iranian Navy to be in response to the U.S. action," it said in an advisory to clients.

"Both tankers were Suezmax-sized. Iran has previously responded tit-for-tat following seizures of Iranian oil cargo."

The sources familiar with the matter, who declined to be identified due to the sensitivity of the issue, said Washington took control of the oil cargo aboard the Marshall Islands tanker Suez Rajan after securing an earlier court order. The tanker's last reported position was near southern Africa on April 22, ship tracking data showed.

The vessel's Greece-based manager, Empire Navigation, and the U.S. Department of Justice did not immediately respond to requests for comment.