A US submarine torpedoed and sank an Iranian frigate in the waters near Sri Lanka on Wednesday, just days after the warship participated in a multi-nation exercise and international fleet review hosted by New Delhi, widening the conflict in West Asia and bringing it into India’s strategic backyard. Track updates on Iran-US conflict
US defense secretary Pete Hegseth confirmed at a media briefing in Washington that the Iranian frigate had been sunk by the US, hours after Sri Lankan officials said the warship was targeted in a submarine attack. The Sri Lankan Navy said it rescued 32 people after it received a distress call while defence secretary Sampath Thuyyakontha told BBC Sinhala 80 bodies had been found.
There was no word on the incident from India’s external affairs ministry or the military. People familiar with the matter said the incident had occurred outside India’s territorial waters after the Iranian warship had completed its participation in the International Fleet Review in Visakhapatnam and the Milan 2026 multi-nation exercise.
Hegseth, while briefing the media on the conflict with Iran that began on February 28 with combined Israeli and US strikes on Iranian cities, said: “In the Indian Ocean, an American submarine sank an Iranian warship that thought it was safe in international waters. Instead, it was sunk by a torpedo, quiet death.”
This is believed to be the first sinking of a ship by torpedo by the US in the Indian Ocean since World War 2.
Former Indian Navy chief Admiral Arun Prakash described the US action as “condemnable”. He said on social media that the sinking of the Iranian warship off the southern tip of Sri Lanka, “with heavy loss of life is a senseless & inflammatory act”.
Prakash added, “Initiating another dimension of violence in this open-ended conflict will spread alarm across the high seas & disrupt global seaborne commerce. Condemnable!”
Despite the official silence on the matter, the US action is unlikely to go down well in New Delhi, which has sought to maintain a delicate balancing act in view of its historical ties with Iran and growing strategic and economic relations with West Asian states, as well as recent efforts to rebuild the relationship with the US after a year of strains over trade issues.
The development came just a day India called for dialogue and diplomacy aimed at an early end to the Iran-US conflict, and highlighted the need to secure the interests of nearly 10 million Indians living in West Asia and prevent disruptions in trade and energy supply chains with potential “serious consequences” for the country’s economy.
Experts in New Delhi also raised questions as to whether the US had kept India in the loop about its naval operations in the Indian Ocean. The experts also noted that the Iranian frigate is unlikely to have been in a heightened state of readiness or resorting to extensive evasive protocols while passing through regional waters.
When the IRIS Dena arrived in India on February 16, the Indian Navy had welcomed it for the multilateral naval exercise Milan 2026 in a social media post, describing it as a reflection of the “long-standing cultural links between the two nations”.
Rear Admiral Shahram Irani, the chief of the Iranian Navy, also visited India around the time of the International Fleet Review last month and met Admiral Dinesh Tripathi, the chief of the Indian Navy, in Visakhapatnam on February 19. Irani discussed issues such as sustainable maritime security through cooperation and synergy among countries in the region with Tripathi.
The IRIS Dena—one of Iran’s newest warships—was a Moudge-class frigate that patrols in deep water for the Iranian navy. It was armed with heavy guns, surface-to-air missiles, anti-ship missiles and torpedoes. It also carried one helicopter. The frigate accompanied by a support ship IRIS Makran, a converted oil tanker, was the centrepiece of a two-ship international tour in 2023. The US. Treasury Department included both ships on a sanctions designation in February 2023 along with eight executives of an Iranian drone manufacturer that supplied the weapons to Russia for use against civilian targets in Ukraine.
At least 17 Iranian naval vessels have been sunk during the ongoing war, said U.S. admiral Brad Cooper, who leads the American military’s Central Command.
“We are also sinking the Iranian navy — the entire navy,” he said in a video message.
With the Americans vowing to use more firepower, the West Asia conflict continues to expand. “We are just getting started. We are accelerating, not decelerating. Iran’s capabilities are evaporating by the hour, while American strength grows fiercer, smarter and utterly dominant,” said Hegseth on Wednesday. “They are toast, and they know it… and we have only just begun to hunt, dismantle, demoralize, destroy, and defeat their capabilities, just four days in. The two most powerful air forces in the world will have complete control of Iranian skies. Uncontested airspace.”
With inputs from agencies