Iranian Navy frigate IRIS Dena sank approximately 40 nautical miles south of Galle, Sri Lanka. CENTCOM confirmed the sinking. Sri Lanka launched a rescue operation and recovered 32 critically wounded sailors; the fate of approximately 148 remaining crew is unknown. Sri Lanka's defence officials stated the attack profile is consistent with a submarine strike. Neither the US nor Iran has formally attributed the method. This is the first Iranian Navy surface combatant sunk in action since Operation Praying Mantis in April 1988.
The Dena's sinking extends the conflict's operational geography to the Indian Ocean — the fourth body of water in five days — and demonstrates that Iran's surface fleet can be engaged far beyond its shore-based missile defences. The location, astride the shipping corridor carrying 60 per cent of Gulf oil exports to Asia, compounds the commercial disruption already created by insurance withdrawal and Hormuz closures.
