In a dramatic escalation of global maritime tensions, a United States submarine has reportedly torpedoed and sunk the Iranian warship IRIS Dena in the international waters of the Indian Ocean. The incident occurred shortly after the vessel departed from India, where it had been participating in a prestigious multi-national naval exercise. The sinking marks a rare instance of submarine-launched torpedo warfare in the modern era and signals that the conflict involving Iran, Israel, and the US has expanded far beyond the confines of the Middle East.
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From Diplomatic Guest to Military Target
The IRIS Dena had recently concluded its stay at the Indian port of Visakhapatnam, where it took part in the MILAN 2026 naval exercises from 15 to 25 February. This biennial event, hosted by the Indian Navy, featured 74 nations and was designed to foster maritime cooperation. The Iranian warship was officially considered a “guest” of New Delhi during its tenure in Indian waters.
However, as the vessel sailed through international waters towards the Gulf, it was intercepted by US forces. US Secretary of Defence, Pete Hegseth, characterised the vessel as a “high-value target,” asserting that military operations against Tehran are no longer confined to the immediate Persian Gulf. US President Donald Trump added that the systematic elimination of Iran’s naval capabilities is a primary objective of the current administration.
Incident Summary: The Sinking of IRIS Dena
| Metric / Detail | Information |
| Vessel Name | IRIS Dena (Mowj-class Frigate) |
| Attacking Unit | United States Navy Submarine |
| Location | International Waters, near Sri Lanka |
| Casualties | 87 confirmed dead; approx. 11 unaccounted for |
| Survivors | 32 sailors rescued by Sri Lankan Navy |
| Preceding Activity | Participant in India’s MILAN 2026 Exercise |
Rescue Operations and Aftermath
The Sri Lankan Navy responded to a distress signal from the frigate on Wednesday. Upon arriving at the coordinates, rescuers found no sign of the ship—only a vast oil slick and sailors struggling in the water. A total of 87 bodies were recovered, while 32 survivors were transported to a hospital in the southern coastal city of Galle.
A video released by the US Department of Defence on social media captured the moment of impact. The footage shows a violent underwater explosion that snapped the warship’s hull, followed by a massive plume of smoke and water. Iranian Foreign Minister Abbas Araghchi condemned the strike as an “act of maritime atrocity,” warning that the United States would soon face “bitter regret” for the attack.
Political Fallout in New Delhi
The sinking has ignited a firestorm of controversy in India. Opposition leaders, including Rahul Gandhi, have criticised Prime Minister Narendra Modi’s government for its perceived “deafening silence” on the matter. Critics argue that an attack on a foreign warship that was, until recently, an official guest of the Indian Navy constitutes a breach of diplomatic etiquette and a threat to India’s regional maritime security.
Former Foreign Secretary Kanwal Sibal noted that while India bears no responsibility for the US action, the strike ignores New Delhi’s sensitivities, particularly as the vessel was in the region upon an Indian invitation. The incident places India in a precarious diplomatic position as it attempts to balance its strategic partnership with Washington against its historical ties with Tehran.