US Submarine Sinks Iranian Warship Off Sri Lanka
AN Iranian warship–the IRIS Dena was sunk around 40km off the waters of Sri Lanka’s Galle, prompting immediate rescue efforts by the Sri Lanka Navy and Sri Lanka Air Force. It was later revealed by the US Department of War (DOW) that the Dena was torpedoed by a US Navy submarine using a Mark 48 torpedo, the first such sinking by the US since the Second World War.
A DOW social media post had Secretary of War Pete Hegseth announcing the sinking as well as video of the strike, though he did not name the Dena. “In the Indian Ocean—an American submarine sunk an Iranian warship, that thought it was safe in international waters. 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 still the War Department—we are fighting to win.”
Initial reports indicated that around 32 crew members were rescued after the vessel issued a distress call, followed by later reports that the warship had been attacked by a foreign submarine. Sri Lankan officials stated that at least 87 remains were recovered with dozens unaccounted for out of the estimated 180-strong crew. The Sri Lankan Navy stated that by the time of their arrival, the ship had gone under with only oil patches and life rafts afloat. “It was within our search and rescue region. So we were obliged to respond as per international obligations”.
The sinking represents a significant and worrying escalation in the conflict with Iran which now extends to even the Indian Ocean, previously mainly limited to the Middle East. Dubbed Operation Epic Fury, the US has since sunk over 20 Iranian Navy vessels, ” including the sinking of an Iranian combatant ship in the Indian Ocean by a US Navy fast attack submarine. I want to remind everybody that this is an incredible demonstration of America’s global reach. To hunt, find and kill an out-of-area deployer is something that only the United States can do at this type of scale,” said Chairman of the Joint Chiefs of Staff General Dan Caine.
The IRIS Dena is a Moudge-class frigate from the Iranian Navy’s Southern Fleet, recently taking part in the MILAN 2026 multinational naval exercise and fleet review in India early last month. The Dena was on its voyage home, just days after US-Israeli strikes in Iran and subsequent attacks across the Middle East by the three countries, affecting Lebanon, Saudi Arabia, Kuwait, United Arab Emirates (UAE) and even Turkiye.