Frigate returning from naval exercise linked to India targeted in torpedo strike; tensions between Washington and Tehran escalate dramatically.

In a dramatic escalation of tensions between the United States and Iran, a U.S. submarine reportedly sank an Iranian naval warship in the Indian Ocean near Sri Lanka, killing at least 87 personnel and raising fears of a widening conflict across the region.

According to international news agency reports, the vessel identified as IRIS Dena, a Moudge-class frigate belonging to the Iranian Navy, was struck by a torpedo launched from an American submarine while sailing through international waters. The warship was reportedly returning home after participating in a multinational naval exercise in India.

The Iranian frigate had previously taken part in the MILAN naval exercise, a major multilateral maritime drill hosted by India that involves navies from across the Indo-Pacific region. The same exercise’s latest edition concluded recently, and the Iranian vessel had begun its return journey when the attack occurred.

While the United States has not officially confirmed the exact casualty figures, U.S. Defence Secretary Pete Hegseth acknowledged that an American submarine carried out the strike. Speaking to reporters, he described the operation as proof of Washington’s global military reach amid its ongoing confrontation with Tehran.

“An American submarine sunk an Iranian warship that thought it was safe in international waters. Instead, it was sunk by a torpedo,” Hegseth said.

Shortly after the strike, the U.S. Department of War released a brief black-and-white video appearing to show a submarine periscope view followed by a distant explosion at sea. Military analysts say it is highly unusual for such footage to be made public so soon after a submarine engagement, as underwater operations are normally kept highly classified.

The incident marks a significant development in the already volatile conflict between the United States and Iran, potentially expanding the war zone into the Indian Ocean region. Strategic waters near Sri Lanka are among the world’s busiest maritime routes, and any escalation could raise serious concerns for international shipping and regional security.

Iran has not yet issued a detailed official response, but regional observers warn that the sinking of a naval vessel — especially one returning from an international exercise — could provoke strong retaliation from Tehran.

Security experts say the episode also highlights how modern warfare is increasingly accompanied by rapid information releases, including combat footage and official statements designed to influence global perception of military actions.

With tensions mounting and the conflict appearing to spread geographically, the international community is closely watching the situation, fearing that further confrontations at sea could trigger a broader regional crisis.Top of Form