US submarine sinks Iranian frigateUS submarine sinks Iranian frigate IRIS Dena off Sri Lanka coast
A US Navy submarine sank the Iranian frigate IRIS Dena in the Indian Ocean off Sri Lanka's southern coast using a single Mk 48 torpedo. US Defense Secretary Pete Hegseth confirmed the strike on March 4, 2026, during a Pentagon briefing on Operation Epic Fury, marking the first such US submarine kill since World War II. Sri Lankan forces rescued 32 survivors from the 180 aboard, with over 80 confirmed dead; the incident expands the US-Iran conflict beyond the Middle East.
- IRIS Dena was a Moudge-class frigate, Iran's most advanced surface combatant.
- Sri Lanka hosted a multinational naval exercise in February with 74 nations, including Iran and the US.
- The last US submarine torpedo sinking was in 1945 against Japanese frigates.
US-Iran Ceasefire War
The United States launched military strikes against Iran on June 26, 2026, in response to a drone attack on a commercial cargo ship in the Strait of Hormuz, calling it a "foolish violation" of the 60-day ceasefire agreement signed just days earlier[2][4][14].
26 June, 09:35 PM
US launches strikes against Iran following commercial ship attack26 June, 04:47 PM
Trump calls Iran drone attack on cargo ship a ceasefire violation
