US Navy Submarine Sinks Iranian Frigate Off Sri Lanka's Coast

In a dramatic escalation of military tensions, a US Navy submarine has reportedly sunk the Iranian frigate IRIS Dena in international waters off Sri Lanka. The Pentagon confirmed the submarine's actions were in response to perceived threats from the Iranian vessel. Following the incident, Sri Lankan forces rescued 32 sailors, with some in critical condition. The IRIS Dena, a modern Moudge-class frigate, was on an international tour when it was attacked. This incident marks a significant moment in the ongoing conflict between the US and Iran, raising concerns about regional stability.

By Narendra Chaudhary Mar 4, 2026, 20:59 IST

US Submarine Engages Iranian Warship

In a significant escalation of tensions between the United States and Iran, a US Navy submarine reportedly launched a torpedo that sank the Iranian frigate IRIS Dena in international waters near Sri Lanka early Wednesday. The Pentagon confirmed that the submarine acted after identifying the Iranian vessel as a potential threat amid rising regional hostilities. Officials noted that the torpedo strike was executed with precision, leading to the swift incapacitation of the frigate.

Watch the moment the US submarine torpedoed the Iranian Navy frigate IRIS Dena off Sri Lanka's coast

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As a result of the incident, Sri Lankan authorities have rescued 32 sailors from the IRIS Dena, with all being transported to Karapitiya Hospital in Galle for treatment of injuries sustained during the sinking. Reports indicate that some survivors are in critical condition, while others are receiving care for burns and shock. U.S. Defense Secretary Pete Hegseth confirmed that the torpedo fired from the submarine was responsible for the sinking.

Dr. Anil Jasinghe, a senior official from the health ministry, reported that one rescued sailor is in critical condition, seven are undergoing emergency treatment, and others are being treated for less severe injuries. The IRIS Dena, a Moudge-class frigate and one of Iran's latest naval assets, is equipped with heavy artillery, surface-to-air missiles, anti-ship missiles, and torpedoes, along with a helicopter. This frigate was part of a two-ship international tour in 2023, which included visits to South Africa and Brazil, accompanied by the support vessel IRIS Makran, a converted oil tanker.