Oil tanker in the Persian Gulf (archive)
Oil tanker in the Persian Gulf (archive)iStock

Iran seized a Vietnamese-flagged oil tanker in the Gulf of Oman last month and still holds the vessel, two US officials told The Associated Press on Wednesday.

Iran's Revolutionary Guard troops took control of the MV Southys, a vessel that analysts suspect of trying to transfer sanctioned Iranian crude oil to Asia, on October 24 at gunpoint, the officials said.

US forces had monitored the seizure, but ultimately didn't take action as the vessel sailed into Iranian waters, according to AP.

Iran celebrated its capture of the vessel in dramatic footage aired on state television, the day before the 42nd anniversary of the 1979 seizure of the US Embassy in Tehran.

Officials at the Vietnamese Embassy in Washington did not immediately respond to a request for comment. Ship-tracking data analyzed by AP from MarineTraffic.com showed the vessel still off Iran's southern port of Bandar Abbas on Tuesday. A satellite photo from Planet Labs Inc. also showed the vessel off Bandar Abbas in recent days.

The report came after Iranian state TV claimed that Iran had foiled an attempt by the US to "steal" oil in the Sea of Oman.

According to the Mehr news agency, there was a confrontation between speedboats belonging to the Iranian Revolutionary Guards and a US ship.

The US ship left the scene, Mehr said, promising that footage would soon follow.

Asked about Iran's assertion of US aggression, Pentagon press secretary John Kirby said it was false and that it was Iran that had seized what he described as a merchant vessel in the Gulf of Oman on October 24.

“It's a bogus claim,” Kirby said of the Iranian assertion. “The only seizing that was done was by Iran." He declined to cite the nationality of the vessel that was seized, saying it was up to that country to discuss it.

In August, Iran attacked an Israeli-owned oil tanker, the MV Mercer Street, as it sailed in the Arabian Sea. Two of the ship's crew members were killed in that attack, which the US promised to repay with an "appropriate response."

In the last few years there have been several close encounters between Iranian and American vessels in the Persian Gulf. The Revolutionary Guard typically patrols the shallower waters of the Persian Gulf and its narrow mouth, the Strait of Hormuz.

One such incident in May of 2020 included a tense encounter between US and Iranian ships in the Persian Gulf.

The US military said at the time that 11 Revolutionary Guards naval vessels from the Guards navy came close to US Navy and coast guard ships in the Gulf, calling the moves “dangerous and provocative”.

Iran’s Revolutionary Guard acknowledged that the incident had taken place, but also claimed that it was American forces who sparked the incident.

In April of 2020, a spokesman for the Iranian Armed Forces said that the Islamic Republic will respond “severely” if US vessels violate its territorial waters.