Tehran/Colombo/Washington, March 5, 2026 – Iran’s Foreign Minister Seyed Abbas Araghchi on Wednesday condemned the sinking of the Iranian Navy frigate IRIS Dena by a U.S. submarine in the Indian Ocean as an “act of state terrorism” and a “grave atrocity,” vowing that the United States would “bitterly regret” setting such a dangerous precedent. The statement came as search and rescue operations continued off the southern coast of Sri Lanka, where the vessel went down after being struck by a single Mark 48 torpedo.
In a strongly worded press conference in Tehran, Araghchi described the attack—confirmed by U.S. Defense Secretary Pete Hegseth—as a “cowardly and unlawful assault on a sovereign warship in international waters.” He accused Washington of escalating the conflict far beyond the Middle East theater and warned of “severe and proportionate consequences” that would extend across multiple domains.
“The United States has crossed a red line that no nation can ignore,” Araghchi declared. “Sinking our ship in the Indian Ocean, far from any declared war zone, is not only a military provocation but a deliberate attempt to terrorize the Islamic Republic and its allies. The U.S. will bitterly regret this precedent. We will respond in a manner and at a time of our choosing, and the response will be devastating.”
The IRIS Dena, a modern Moudge-class frigate equipped with anti-ship and surface-to-air missiles, torpedoes, and helicopter capabilities, sank rapidly on March 4, 2026, approximately 40 nautical miles off Galle, Sri Lanka. The ship was returning to Iran after participating in multinational exercises in the Bay of Bengal hosted by India. A distress call reported an underwater explosion at 5:08 a.m. local time; the vessel split along its port quarter and went down before Sri Lankan Navy vessels could arrive.
Sri Lankan authorities recovered 32 survivors—many in critical condition—and 87 bodies by late Wednesday. An estimated 61 crew members remain missing from a total complement of around 180. Sri Lanka’s Foreign Ministry confirmed the vessel’s identity and expressed deep concern over the incident occurring in international waters near its exclusive economic zone.
U.S. officials defended the strike as a targeted response to perceived threats posed by Iranian naval forces in the region. Pentagon briefings described the IRIS Dena as Iran’s “prize ship” and emphasized that the attack occurred in international waters after the frigate was deemed to be maneuvering in a manner consistent with hostile intent. A declassified video released by the Pentagon showed the torpedo impact, with a massive plume of water erupting as the warship broke apart.
The sinking marks the first time a U.S. submarine has sunk an enemy surface vessel with a torpedo in combat since World War II. It represents a significant escalation in the U.S.-Israeli campaign against Iran, now in its sixth day, which has already included airstrikes that killed Supreme Leader Ayatollah Ali Khamenei and degraded much of Iran’s air defense network.
Iran has already launched multiple waves of ballistic missiles, cruise missiles, and drones targeting Israeli military sites and U.S. bases in Gulf states, including deadly strikes in Kuwait, Qatar, Bahrain, Saudi Arabia, and the UAE. The loss of IRIS Dena—combined with earlier damage to other naval assets—further weakens Iran’s surface fleet projection in the Indian Ocean and Persian Gulf.
Araghchi’s warning of revenge echoed earlier statements from IRGC commanders, who have promised asymmetric responses targeting U.S. naval assets, energy infrastructure, and commercial shipping lanes. Analysts warn that Iran could intensify attacks on Gulf oil facilities, activate proxy forces in Iraq, Yemen, and Lebanon, or attempt to disrupt global maritime traffic beyond the Strait of Hormuz—already effectively closed to most commercial tankers due to Iranian threats.
The economic fallout continues to intensify. Brent crude prices remain elevated near $82 per barrel, while QatarEnergy’s force majeure on LNG exports has removed a substantial portion of global supply. Major container lines have suspended Persian Gulf services, rerouting around the Cape of Good Hope and adding weeks to transit times.
Sri Lanka, maintaining strict neutrality, has focused on humanitarian response while calling for de-escalation to prevent further incidents in South Asian waters. President Anura Kumara Dissanayake expressed condolences for the lost lives and urged all parties to respect international maritime law.
The United Nations Security Council remains paralyzed by veto threats, with Russia and China condemning the sinking as “piracy on the high seas” and the U.S. defending it as self-defense. Diplomatic efforts—mediated in part by Oman, Qatar, and India—have so far failed to produce a ceasefire.
As the conflict shows no signs of abating, Araghchi’s vow that the U.S. will “bitterly regret” the attack signals Tehran’s intent to respond forcefully, potentially expanding the theater of operations and raising the risk of a wider regional or even global confrontation.
