Iran’s Navy chief has issued a stark warning of “deadly retaliation” after dozens of sailors were killed when the Iranian warship IRIS Dena sank in the Indian Ocean earlier this month.

Speaking to state broadcaster Press TV, naval commander Shahram Irani said Tehran would respond decisively, cautioning adversaries that any retaliation would be unexpected. “We will not forget the enemy’s crime, and we will exact retribution for the blood of our martyrs,” he said, adding that the response would come “from where it is least expected.”

The statement follows earlier remarks by army chief Amir Hatami, who on March 14 said the deaths of the crew “will not go unanswered,” according to Al Jazeera citing the Islamic Republic News Agency. Hatami noted that the vessel had completed a “peaceful mission” and was returning from military exercises at the time of the attack.

Iranian officials have alleged that the frigate was struck by a US submarine near Galle, describing the incident as a “war crime.” Foreign ministry spokesperson Esmaeil Baqaei said the ship had been invited by the Indian Navy for a joint exercise and port visit prior to the incident.

The warship sank south of Sri Lanka on March 4 after being hit by a torpedo about 20 nautical miles west of Galle. Of the roughly 180 crew members onboard, around 87 were reported dead, while 32 survivors were rescued by the Sri Lanka Navy and taken to hospitals in the coastal city.

In the aftermath, India deployed vessels, including INS Tarangini and INS Ikshak, along with Boeing P-8I Poseidon aircraft, to assist Sri Lanka-led search and rescue operations.