The statement comes as global oil-shipping costs are increasing.
Tehran had previously disclosed only one attack in the Red Sea, occurring on Oct. 11, when the National Iranian Tanker Co. said one of its vessels, the Sabiti, had been struck near the Saudi coastline. The company said the ship was likely hit by two missiles.
Iran didn’t cast blame in the letter to the International Maritime Organization about the attacks.
But Tehran said, “We believe that this is an attack organized by one or more states, since two other Iranian flagged [very large] tankers were similarly attacked in the same approximate area” and with “ similar damages to the ships.”
“A major concern in this respect is that the organized and directed pattern of these attacks within a short time and similar locations have rendered the Red Sea as an unsafe route for ships to adopt for their voyages,” the letter, dated Oct. 30, said.
The Iranian embassy in London and the IMO didn’t respond to requests for comment.
In the letter, the Iranian government said the Happiness 1 and the Helm were targets of the previously undisclosed attacks, in April and August respectively. The the National Iranian Tanker Co. said the Happiness 1 had suffered “engine failure and loss of control” and the Helm “technical issues.”
The first incident occurred just before several Saudi and Emirati tankers were struck by acts of sabotage beginning in mid-May The U.S. blamed Iran for the incidents and later said Iran was responsible for a strike against oil facilities in the Saudi Arabia in mid-September.
Iran has denied involvement in the attacks.
All three incidents on the Iranian vessels took place near Saudi Arabia’s coastline, according to shipping tracking data. Iran said those responsible would be liable under maritime convention that calls for prosecution or extradition of anyone committing maritime attacks.