US Submarine Torpedoes Iranian Frigate IRIS Dena Returning From India’s MILAN Naval Exercise, 87 Sailors Dead Near Sri Lanka
A U.S. submarine torpedoed and sank the Iranian naval frigate IRIS Dena in the Indian Ocean off Sri Lanka on Wednesday, and killed at least 87 sailors and left dozens missing in an attack that has drawn attention in India because the vessel had just returned from participating in a major naval exercise hosted by the Indian Navy in Visakhapatnam.
U.S. Defense Secretary Pete Hegseth confirmed that an American submarine carried out the strike, and described it as part of Washington’s expanding military campaign against Iran.
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| File Photo: Indian Navy welcomes IRIS Dena of the Iranian Navy this Feb; Via: IN_HQENC |
.@SECWAR “In the Indian Ocean—an American submarine sunk an Iranian warship, that thought it was safe in international waters.
— DOW Rapid Response (@DOWResponse) March 4, 2026
Instead, it was sunk by a torpedo—Quiet Death.
The first sinking of an enemy ship by a torpedo since World War 2. Like in that war—back when we were… pic.twitter.com/Y97YQBxQza
He said the attack marked the first time since World War II that the United States had destroyed an enemy ship using a submarine-launched torpedo, and called the strike a “quiet death” and a demonstration of U.S. naval reach across global waters.
Sri Lankan authorities said the frigate issued a distress call shortly after dawn about 40 kilometres south of the port city of Galle. According to Sri Lanka’s Foreign Minister Vijitha Herath, naval vessels and aircraft were immediately dispatched to the site.
https://t.co/PiqQpVIrMu pic.twitter.com/Wc1e0B0um7
— Department of War 🇺🇸 (@DeptofWar) March 4, 2026
By the time rescue teams arrived, the warship had already sunk, leaving only an oil slick and debris floating on the surface. Officials said 32 Iranian sailors were rescued alive and taken to hospitals in southern Sri Lanka, while dozens of bodies were recovered from the surrounding waters as search operations continued.
Sri Lankan police later confirmed that at least 87 bodies had been recovered, with many more crew members still missing. Commander Buddhika Sampath, a spokesman for the Sri Lankan Navy, said the rescue mission was launched under international maritime obligations because the sinking occurred within Sri Lanka’s designated search-and-rescue zone in the Indian Ocean.
The frigate reportedly carried around 180 personnel and had recently taken part in the 2026 International Fleet Review and MILAN naval exercises hosted by India in the eastern port city of Visakhapatnam.
Earlier this year the Indian Navy’s Eastern Naval Command publicly welcomed IRIS Dena to the exercise, and described the visit as a reflection of long-standing maritime engagement and cultural ties between India and Iran.
Welcome! | خوش آمدید!
— Eastern Naval Command 🇮🇳 (@IN_HQENC) February 17, 2026
🇮🇳🤝🇮🇷 Indian Navy welcomes IRIS Dena, of the Iranian Navy, on her arrival at #Visakhapatnam to participate in #IFR2026_India and #MILAN2026, reflecting long-standing cultural links between the two nations.@India_in_Iran #BridgesOfFriendship… pic.twitter.com/O77v2qNJHJ
The fact that the vessel was struck while returning from an Indian naval event has sparked political commentary in India, where opposition figures questioned New Delhi’s silence following the attack. Congress spokesperson Pawan Khera wrote on X that the Iranian warship had been “India’s guest” at the naval exercise and asked whether the government would express condolences or raise the incident diplomatically.
Another Congress leader, Supriya Shrinate, also questioned what role India was playing as the incident unfolded near its broader strategic neighbourhood in the Indian Ocean.
Some analysts and online community notes have pushed back on those claims, and noted that the attack occurred in international waters outside India’s territorial jurisdiction and therefore did not fall within India’s legal authority to prevent.
🇮🇳🤝🇮🇷Khoshomadid! #IndianNavy welcomes IRIS Dena, a Moudge Class Frigate of the Iranian Navy at #Visakhapatnam, #AndhraPadesh for participation in the Multilateral Naval Exercise #MILAN2024.
— Eastern Naval Command 🇮🇳 (@IN_HQENC) February 19, 2024
This is a reflection of our shared historical & cultural linkages. 🌊⚓🚢… pic.twitter.com/TTbWgqeuGM
Still, the episode once again highlights how the widening U.S.–Israel war against Iran is spilling into maritime zones close to South Asia, including sea lanes routinely used by Indian naval forces and commercial shipping.
The sinking of IRIS Dena marks one of the most significant naval losses for Iran in the current conflict and signals an escalation of the war into the wider Indian Ocean theatre. While the United States says one of its objectives is to dismantle Iran’s naval capabilities, Tehran has warned that it will retaliate against U.S. and allied assets across regional waters and strategic shipping routes.
Contingent from #IRISDena marching in Vishakhapatnam during #Milan-2026 naval exercise on 19th February. IRIS Dena sunk this morning near #Galle, Srilanka by USA submarine, fourth such kill after WW2. War reaches in #IndianOcean . #IranIsraelWar #IranWar #IndianNavy pic.twitter.com/skDCJlbaAp
— Krishna Mohan Mishra (@kmmishratv) March 4, 2026
With the vessel having just departed an Indian naval exercise and the incident unfolding near Sri Lanka, the episode shows how a war that began with airstrikes in the Middle East is increasingly intersecting with South Asia’s maritime geography, even as the Indian government has so far made no public statement on the attack.