US to 'Bitterly Regret' Torpedoing Iran's Frigate Dena in International Waters: FM 

Thursday, 05 March 2026 12:04 PM

File photo of Iran's Dena destroyer

Iranian Foreign Minister Abbas Araghchi has vowed that the United States will “bitterly regret” sinking Iran’s Frigate Dena in international waters that led to the killing of dozens of sailors.

The attack occurred hundreds of miles across the Indian Ocean - off the southern coast of Sri Lanka - away from the Persian Gulf, where a US-Israeli military coalition has been striking Iran in an unprovoked war of aggression since Saturday.

“The U.S. has perpetrated an atrocity at sea, 2,000 miles away from Iran’s shores. Frigate Dena, a guest of India’s Navy carrying almost 130 sailors, was struck in international waters without warning. Mark my words: The U.S. will come to bitterly regret precedent it has set,” Araghchi said in a post on X on Thursday.

Frigate IRIS Dena was torpedoed and was sunk by a US submarine on Wednesday. According to Sri Lanka's deputy foreign minister, it was heading back to Iran from an eastern Indian port.

“An American submarine sank an Iranian warship that thought it was safe in international waters,” said US Defense Secretary Pete Hegseth at the Pentagon, adding, “Instead, it was sunk by a torpedo. Quiet death.”

According to hospital authorities in the Sri Lankan port city of Galle, a total of 87 bodies were brought in by military rescuers who responded to an early morning distress call.

Sri Lankan authorities noted that another 32 sailors were rescued and were being treated at a hospital. 

However, they said that around 60 sailors were likely unaccounted for from an estimated 180 people on board.

Frigate IRIS Dena had taken part in a naval exercise organized by India in the Bay of Bengal from February 18 to 25.

Meanwhile, The Islamic Revolutionary Guard Corps (IRGC) announced that its naval forces struck an US oil tanker in the northern Persian Gulf earlier on Thursday, setting it ablaze.

In response to the US-Israeli aggression against Iran, the naval and aerospace units of the IRGC and the Islamic Republic’s national military forces have launched massive missile strikes against US military assets in regional countries and on targets in the Israeli-occupied territories since the weekend.

Iran’s escalating strikes have prompted Washington to close its embassies, urging Americans to flee the region.