New Delhi: Iranian ship IRIS Dena was sailing towards Sri Lanka on a diplomatic invite, but the Moudge-class frigate had to abort the journey and “remain in international waters” as the invitation was revoked after tensions ratcheted up between the US and Iran, according to a report in Jaffna Monitor.
The report says that the 11-hour wait in the Indian Ocean made the warship vulnerable to US strikes, and it was torpedoed by a US submarine on 4 March, sinking it within minutes.
According to corroboration from multiple sources familiar with the incident, reports Jaffna Monitor, the invitation was extended during MILAN 2026, a multinational naval exercise hosted by India in the port city of Visakhapatnam.
During the exercise, the Sri Lankan Navy’s representatives reportedly invited the Iranian frigate to conduct a courtesy port call, which is a routine gesture of goodwill intended to deepen maritime cooperation.
However, after the end of the naval exercise on 25 February, the situation in the West Asian region dramatically changed as Tehran found itself engaged in the escalating military conflict with the US and Israel.
As the United States and Iran moved toward open conflict, Colombo reassessed its diplomatic position, the report says.
According to sources familiar with internal discussions in Colombo, the report adds, Sri Lankan officials concluded that allowing an Iranian warship amid the conflict would carry diplomatic risks.
Therefore, the earlier invitation was reversed, and IRIS Dena was instructed not to proceed towards its planned destination. By the time the message reached the ship, the Iranian vessel had nearly reached 40 nautical miles south of the port of Galle, claims the report.
“Details emerging from multiple sources familiar with naval communications in Iran, India and Sri Lanka suggest the ship’s final movements may have been shaped not only by the escalating United States–Iran confrontation, but also by a sudden shift in Sri Lanka’s diplomatic posture — one that left the vessel waiting in open waters for nearly eleven hours,” says the report.
A source in direct communication with the ship told the publication, “When the message came telling us not to proceed, we had no option but to remain in international waters and wait.”
The delay in providing port access to the Iranian Frigate left it floating on the open waters for approximately eleven hours. Regional maritime analysts emphasised that long waiting exposed the vessel to hostile action.
On 4 March, a U.S. Navy fast-attack submarine with a Mark 48 torpedo sank the Iranian frigate IRIS Dena within three minutes. This left 80 crew members dead, with 32 to 37 survivors rescued by Sri Lankan authorities.
Later, US Secretary of War Pete Hegseth called the sinking a “quiet death”. He also said it was “the first sinking of the enemy ship by a torpedo since the Second World War”.
The survivors were brought to a hospital in Galle, while the rescue team continued to recover bodies from the sea after the deadly sinking.
Also Read: Iranian naval ship Lavan with crew of 184 docked in Kochi same day US torpedoed IRIS Dena
Divergent accounts
After the US sinking of the Iranian ship, divergent accounts have emerged from Colombo. Sri Lankan President Anura Kumara Dissanayake on Wednesday told reporters that Iran had formally requested permission earlier in the month for naval vessels to visit Sri Lanka.
“On the 26th of last month (February), Iran requested permission from our Ministry of Foreign Affairs for three naval vessels to enter our port between March 9 and March 13,” added Dissanayake.
Officials in Colombo have also suggested that the Iranian warship may have sought emergency refuge in Sri Lanka after it became unsafe for the vessel to return to Iran amid the escalating conflict.
A source familiar with the incident stated that they characterise the “sudden denial” of entry and the subsequent 11-hour delay as a perceived betrayal by Sri Lankan authorities.
The Sri Lankan authorities are yet to provide the timeline about the communication exchanged with IRIS Dena in its final hours.
(Edited by Ajeet Tiwari)
Also Read: Another Iranian vessel seeks Sri Lanka’s help, day after US submarine strike sunk IRIS Dena