Iranian Warship IRIS Dena Sinks Off Sri Lanka; US Submarine Strike Reported

On March 4, 2026, the Iranian naval frigate IRIS Dena sank approximately 40 nautical miles off Sri Lanka's southern coast after issuing a distress call. Sri Lankan Navy and Air Force conducted a rescue operation, saving 32 sailors who were hospitalized in Galle. Reports indicate the ship was struck by a torpedo from a US submarine, marking a significant escalation in the US-Iran conflict. Casualty estimates vary, with around 80 dead and over 100 missing. The vessel had recently participated in India's MILAN 2026 naval exercise. Sri Lankan officials emphasized their rescue efforts under international maritime obligations, while the exact cause and responsible party remain officially unconfirmed by Sri Lanka.