Iran’s Foreign Minister Seyed Abbas Araghchi on Thursday has warned that the United States will “bitterly regret" its action after a US submarine struck an Iranian naval vessel near Sri Lanka.

In a post on X, Araghchi said the United States had carried out “an atrocity at sea" far from Iran’s shores. He stated that the frigateDena, carrying nearly 130 sailors and a guest of the Indian Navy, was attacked in international waters without warning.

The U.S. has perpetrated an atrocity at sea, 2,000 miles away from Iran’s shores.Frigate Dena, a guest of India’s Navy carrying almost 130 sailors, was struck in international waters without warning.

Mark my words: The U.S. will come to bitterly regret precedent it has set.pic.twitter.com/cxYiI9BLUk

— Seyed Abbas Araghchi (@araghchi)March 5, 2026

The Iranian Navy frigate IRIS Dena was sunk in the early hours of March 4, about 40 nautical miles south of Galle, Sri Lanka. The incident marks the first major naval casualty of the US-Israel-Iran war in the deep waters of the Indian Ocean, signalling what intelligence sources described as a dangerous spillover into India’s maritime region.

The vessel was returning home using a standard westward route after taking part in India’s MILAN 2026 multinational naval exercise and International Fleet Review in Visakhapatnam weeks earlier.

Sri Lankan Navy and Defence Ministry sources described the incident as a classic submarine torpedo attack. Distress calls between 5:08 am and 5:30 am local time reported a massive underwater explosion that caused severe hull damage and rapid flooding. The ship disappeared from radar and sank within minutes.

US Defence Secretary Pete Hegseth confirmed that an American submarine carried out the strike, saying the warship was sunk by a torpedo.

Hospital authorities in Galle said 87 bodies were brought ashore by rescuers responding to the distress call. Another 32 sailors were rescued and taken to hospital, while about 60 people remained unaccounted for from an estimated 180 on board.

Source: World News in news18.com, World Latest News, World News