IRIS Dena

The IRIS Dena was an Iranian frigate that was sunk by a United States submarine in international waters near Sri Lanka in early March 2026. The incident resulted in the deaths of over 100 Iranian sailors. The sinking occurred amidst heightened tensions in the Indian Ocean. The event became newsworthy due to the high number of casualties, the involvement of a US submarine, and the subsequent rescue and repatriation efforts undertaken by Sri Lanka. Sri Lanka rescued dozens of sailors, some of whom required hospitalization, and is in the process of repatriating the remains of the deceased sailors to Iran. The incident has drawn international attention, with some questioning India's role as a security provider in the region. The presence of Australian troops on board the US submarine, as part of AUKUS training arrangements, has also been revealed. The sinking of the IRIS Dena has significantly increased tensions in the region and complicated Sri Lanka's efforts to remain neutral in the conflict.