US Secretary of Defense Pete Hegseth said Wednesday that a US submarine sank an Iranian warship, in international waters – killing more than 80 crew according to authorities in Sri Lanka who launched a rescue mission.
Iran identified the vessel as the Iris Dena and vowed vengeance for what it described as an "atrocity."
"An American submarine sunk an Iranian warship that thought it was safe in international waters," Hegseth said during a press conference at the Pentagon. "Instead, it was sunk by a torpedo."
The Pentagon released video of the attack showing a ship that experiences a massive explosion by its stern as well as what appeared to be still frames showing the ship sinking.
Sri Lanka's foreign minister Vijitha Herath said the country's navy responded to a distress call on Wednesday.
"A vessel belonging to the Iranian Navy by the name of Iris Dena, was sinking is what we know based on the distress call which we received at 5.08 a.m.," he told parliament. "By 6 a.m. we dispatched boats to the scene while the Air force also joined rescue efforts."
At least 87 bodies have been recovered so far, according to Sri Lankan officials, while some 32 others were rescued by the Sri Lankan Navy.
Some 130 people were believed to have been on board the vessel when the first distress call was received on Wednesday, according to Iran's foreign minister Abbas Araghchi.
"The US has perpetrated an atrocity at sea, 2,000 miles away from Iran's shores," Araghchi said on X. "Mark my words: The US will come to bitterly regret precedent it has set."
Destroying Iran's navy has been one of the most cited objectives of senior US administration officials regarding the ongoing military campaign that started over the weekend. Adm. Brad Cooper, commander of US Central Command, said ina recorded video messageon Tuesday that the US has destroyed more than 17 Iranian ships thus far, including "the most operational Iranian submarine that now has a hole in its side."
Chairman of the Joint Chiefs of Staff Gen. Dan Caine said it was the first time a US attack submarine had used a torpedo to sink a combat ship since 1945.
It was not immediately clear which event he was referring to, but the USS Torsk destroyed multiple Japanese combat ships in 1945.
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Torpedoes have been used since then, dropped from aircraft and not in combat. In 1951, a US attack squadron launched torpedoes on a dam in South Korea, blocking advancing enemy forces, according to theUS Navy. In 1999, a US attack submarine successfully used a torpedo to sink an oil ship after other efforts with explosives had failed to scuttle the ship.
Uneasy focus on India
The IRIS Dena had been sailing home from an east Indian port, where it had participated in an international naval conference hosted by India in February.
"Indian Navy welcomes IRIS Dena, of the Iranian Navy, on her arrival at Visakhapatnam," India's Eastern Naval Command wrote in a post on X on February 17.
A contingent of Iranian sailors marched in a big parade in the port city last month.
A US Navy admiral also attended the gathering, but Washington did not send any ships to India.
"The sinking of the IRIS Dena just hours after it left Indian waters is a massive blow to New Delhi's regional credibility," said Sushant Singh, a lecturer in South Asian Studies at Yale University.
He noted that while the Iranian ship was in international waters, it was "going from an Indian fleet review, through what is not an active war zone, and definitely an area of India's influence."
Singh said: "That is why it crosses a thick red line."
India's "non-negotiables" are "protecting commerce and energy routes, avoiding entanglement in US–Iran escalation, and preventing any normalization of third‑party kinetic actions so close to its maritime periphery," he added.
"All of them have been challenged by the US naval action," Singh said.
India hasn't publicly commented on the incident. CNN has reached out to its foreign ministry and navy for a response.
This story has been updated with additional reporting.
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