US Submarine Sinks Iranian Warship IRIS Dena Off Sri Lanka
A US submarine has sunk the Iranian warship IRIS Dena off the coast of Sri Lanka, a strike confirmed by US Defense Secretary Pete Hegseth on March 4, 2026. The incident, which resulted in significant casualties, marks a major escalation in the ongoing US-Iran conflict and occurred as the Iranian frigate was returning from naval exercises in India.
Key Highlights
- US Defense Secretary Pete Hegseth confirmed the sinking of the IRIS Dena.
- The Iranian warship was struck by a US submarine's torpedo near Sri Lanka.
- Incident resulted in over 80 reported deaths and 32 rescued sailors.
- IRIS Dena was returning from India's MILAN 2026 naval exercises.
- This marks a significant escalation in US-Iran hostilities.
- It is the first US submarine torpedo sinking since World War II.
The Iranian warship IRIS Dena was sunk by a US submarine off the southern coast of Sri Lanka on March 4, 2026, marking a dramatic escalation in the ongoing conflict between the United States and Iran. US Defense Secretary Pete Hegseth confirmed the strike, stating it was the first time an American submarine had sunk an enemy vessel with a torpedo since World War II.
The incident unfolded as the IRIS Dena, a Mowj-class frigate with an estimated 180 crew members, was returning from the MILAN 2026 multinational naval exercises held in Visakhapatnam, India. The vessel issued a distress call at dawn on Wednesday after reportedly being hit by a torpedo. Sri Lankan authorities swiftly launched a search and rescue operation, deploying naval vessels and aircraft.
Reports on casualties vary, but indicate a significant loss of life. Sri Lankan Foreign Minister Vijitha Herath stated that 32 critically wounded sailors were rescued by the Sri Lankan navy and received medical treatment in Galle. While some initial reports indicated 101 people missing, one dead, and 78 injured, Sri Lanka's Deputy Foreign Minister Arun Hemachandra later confirmed that at least 80 Iranian sailors had died in the attack.
The attack occurred in international waters, approximately 20 to 44 nautical miles (81km) off the southern coastal city of Galle, Sri Lanka, outside the island nation's territorial waters but within its economic zone. Sri Lankan navy spokesman Commander Buddhika Sampath noted that while the incident was beyond their territorial waters, Colombo was committed to providing support for rescue efforts.
Defense Secretary Hegseth, during a Pentagon press briefing on Operation Epic Fury, described the attack as a "quiet death" and emphasized America's global reach. He highlighted that this was the first US sinking of an enemy ship by torpedo since World War II. However, General Dan Caine, Chairman of the Joint Chiefs of Staff, later clarified that it was specifically the first time an *American* fast-attack submarine had achieved such a kill since 1945, acknowledging other instances by different nations such as a Pakistani submarine in 1971 and a British submarine in 1982.
This strike is part of a broader intensification of military action by the US and Israel against Iran. The context includes ongoing air strikes on Iran, with previous reports of the US military destroying multiple Iranian naval vessels and targeting Iran's naval strength. The sinking of the IRIS Dena in the Indian Ocean, near India's strategic waters, has significant geopolitical implications, particularly for India, given the vessel's participation in a recent Indian naval exercise. Experts view this as a further escalation of the Iran crisis, spreading turbulence to the Indian Ocean. The Iranian government has yet to officially comment on the incident.
Frequently Asked Questions
What is the key incident that occurred off the coast of Sri Lanka?
A US submarine sank the Iranian warship IRIS Dena using a torpedo off the southern coast of Sri Lanka on March 4, 2026.
Who confirmed the attack and what was its significance?
US Defense Secretary Pete Hegseth confirmed the attack, highlighting it as the first time an American submarine had sunk an enemy ship with a torpedo since World War II.
What was the Iranian warship, IRIS Dena, doing in the region?
The IRIS Dena was returning to Iran after participating in the MILAN 2026 multinational naval exercises, hosted by India in Visakhapatnam.
What were the human casualties reported from the sinking?
While initial reports varied, Sri Lankan officials confirmed rescuing 32 sailors. Later statements from Sri Lankan Deputy Foreign Minister indicated at least 80 Iranian sailors died in the attack.
How does this incident affect the broader geopolitical situation?
This sinking represents a significant escalation in the ongoing hostilities between the US/Israel and Iran, extending the conflict into the Indian Ocean and raising concerns about regional stability, particularly for countries like India.