In the Indian Ocean, very close to the southern coast of Sri Lanka, more than a hundred people are missing after a presumed submarine attack on the Iranian frigate IRIS Dena, a warship that was part of Tehran's naval projection in international waters and whose presence in the region had gone publicly unnoticed until now.
The Sri Lankan navy has confirmed that they rescued 32 people after receiving a distress call from the ship on Wednesday at dawn. Local authorities, although initially reported to international agencies that it was probably a submarine attack, have not officially specified the authorship or the exact circumstances of the frigate's sinking.
"Although the incident occurred outside our waters, it was within our search and rescue area. Therefore, we were compelled to respond in accordance with international obligations," explained Budhika Sampath, military spokesperson for this South Asian country. "We found people floating in the water, rescued them, and then, when we asked, we discovered they were from an Iranian ship."
Sri Lankan authorities believe there were 180 people on board, although the exact number of missing persons is unknown. Local officials have stated that there were around 140 missing persons.
The sinking occurred near Galle, a historic port city in the south of the country, strategically located on one of the world's busiest maritime routes, through which a substantial part of global energy trade flows.
Foreign Minister Vijitha Herath explained to Parliament that the Sri Lankan Navy received information at 6:00 a.m. that the ship IRIS Dena was in danger, and the island nation dispatched ships and air force planes on a rescue mission. The minister stated that his government will "take appropriate action," without offering details on investigations or whether they have been in contact with Tehran.
On land, the injured were taken to the National Hospital of Galle, where images showed an unusual security deployment: ambulances coming and going under the surveillance of armed personnel and a cordoned perimeter at the southern naval headquarters of the country. Sri Lankan authorities justified the secrecy surrounding the rescue images by stating that the operation involved military resources from a third country.
"It appears to be consistent with an attack by a submarine," declared a senior official to The Indian Express, an Indian newspaper with an English edition. "However, the responsible submarine has not been identified, and the investigation continues," he added.
Another official stated that the government could not confirm or rule out the involvement of a U.S. submarine operating in the region. "U.S. Navy Ohio-class submarines routinely patrol the Indian Ocean from the U.S. military base in Diego Garcia (a strategic British-controlled island facility used for operations in the Middle East and Asia). We are examining sightings and maritime tracking data," he stated.
The IRIS Dena frigate was returning to Iran after participating in military exercises in Visakhapatnam, on the east coast of India, on the shores of the Bay of Bengal, where it operated alongside warships from 74 nations. The exercise concluded on February 25, and just three days later, the United States and Israel carried out the so-called Operation Epic Fury against Iranian targets.
The IRIS Dena, commissioned into the Iranian navy in 2021, is a domestically manufactured frigate that is part of the Islamic Republic's effort to expand its operational range beyond the Persian Gulf. The ship displaces approximately between 1300 and 1500 tons and is equipped with a range of anti-ship missiles, naval cannons, and torpedo launchers. It also includes a helicopter landing platform and radar systems capable of tracking multiple targets.
An Indian military analyst consulted emphasized that the frigate would have, among other systems, Qader anti-ship missiles, a 76-millimeter cannon, and torpedo capability, suggesting that it was a fully operational asset.
In recent years, Tehran has intensified its deployments in distant waters —including the Atlantic and the Indian Ocean— as a symbolic challenge to the United States and Western powers, and as a demonstration of its military strength despite international sanctions.