A United States submarine sank an Iranian warship in the Indian Ocean near Sri Lanka, killing at least 87 sailors, amid the US-Israeli war against Iran.

Sri Lankan authorities said the vessel, identified as the IRIS Dena, went down about 40km off the country’s southern coast after issuing a distress call. The navy recovered 87 bodies and rescued 32 survivors. About 180 people were believed to have been on board.

US Defence Secretary Pete Hegseth confirmed the strike at a Pentagon briefing.

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








Screenshot from a video released by the US Department of Defense on March 4, 2026 showing what the Department of Defense says is periscope footage of a US Navy submarine firing on and sinking an Iranian warship in the Indian Ocean. Photo: AFP / Lehtikuva


The Pentagon released video which it said showed the moment of impact. The footage captured an explosion beneath the stern of a vessel, lifting the rear section out of the water before the ship broke apart and sank. Reuters and the BBC reported that the images matched the profile of the IRIS Dena, though the exact date of filming was not verified.

Sri Lanka’s navy spokesman Commander Buddhika Sampath said rescue crews reached the scene after receiving the distress signal but found no intact vessel. “We found people floating in the water and rescued them,” he told reporters. “Later on, we found upon inquiring that they belonged to the Iranian ship.”

The IRIS Dena had taken part in the Milan 2026 naval exercise in the Bay of Bengal, hosted by India from 18 to 25 February. The Indian Navy had posted images of the frigate arriving in Visakhapatnam, describing the visit as a sign of ties between the two countries. India’s foreign ministry later rejected claims that US naval forces were using Indian ports during the conflict, calling such reports “fake and false”.

The sinking marks a further escalation in a war that began with joint US and Israeli strikes on Iranian targets. The White House said US forces have struck or sunk more than 20 Iranian vessels since the campaign began. At least 17 Iranian naval ships have been destroyed, according to US Central Command.

Hegseth said the submarine attack was the first time since the Second World War that a US submarine had sunk an enemy ship with a torpedo. 

Iranian state media reported that the death toll from five days of air strikes across the country had exceeded 1,000, with more than 6,000 wounded. The figures were not independently verified.

The United Nations said about 100,000 people fled Tehran in the first two days of the bombing. The International Atomic Energy Agency reported no damage to facilities containing nuclear material, though it called for restraint to avoid a wider risk.

In Washington, the US Senate voted 52 to 47 against advancing a resolution that sought to limit President Donald Trump’s authority to continue military action against Iran. The measure required 60 votes to proceed.

White House press secretary Karoline Leavitt said the administration aimed to destroy Iran’s navy and ballistic missile capacity and to ensure Iran “can never obtain a nuclear weapon”. She told reporters that Iran’s leaders were “paying in blood” for attacks on US interests.

The conflict has spread beyond Iran’s borders. Israel launched a new wave of strikes across Tehran on Wednesday night, according to the Israeli military. Hezbollah said it had fired rockets at Israeli positions in response to Israeli air raids in Lebanon. Lebanon’s health ministry reported 72 deaths since fighting resumed this week.

Sri Lanka has called for restraint and said it remains neutral. Foreign Minister Vijitha Herath told parliament that the rescue operation took place outside Sri Lankan territorial waters but within its search and rescue zone.

HT