The US Indo-Pacific Command (INDOPACOM) posted on X on 8/3, challenging Iran's claims regarding the sunken vessel. "Iran claims the IRIS Dena was unarmed – false. The law of armed conflict allows the use of force to target and destroy military objectives – true. US forces planned in advance, and Sri Lanka rescued survivors in accordance with the law of armed conflict – true", INDOPACOM stated.

The IRIS Dena, an Iranian frigate, was sunk by a US submarine in the Indian Ocean on 4/3. This marks the first time Washington has attacked Tehran outside the Middle East since the conflict erupted in late 2. Iran strongly protested the US action, stating the IRIS Dena was returning home after a naval exercise in India and was defenseless.

Iranian frigate IRIS Dena. Photo: Wikimedia Commons

Iran's Deputy Foreign Minister Saeed Khatibzadeh told reporters on 6/3 that the IRIS Dena had arrived in the region at the invitation of Indian friends and participated in an international exercise. Khatibzadeh asserted that the ship was ceremonial, carried no cargo, and was unarmed.

US Secretary of Defense Pete Hegseth previously described the IRIS Dena as an Iranian "capital warship" and added that it had "died in silence". Iranian Foreign Minister Abbas Araqchi called the attack an "act of brutality at sea" and stressed that the ship was "a guest of the Indian navy" at the time.

Experts suggest that ships participating in such exercises are typically not equipped with a full complement of combat ammunition. During exercises, ships carry only a limited amount of ammunition, tightly controlled for specific drills. "That is a requirement of the Indian navy and also a condition for most other countries when hosting similar events", Rahul Bedi, an independent defense analyst in India, told the Associated Press.

India's Ministry of Defense stated that the ships fired live ammunition during naval gunnery and anti-aircraft drills. Meanwhile, an Indian navy official said the IRIS Dena had trained with warships from other nations and that the Iranian frigate "was not necessarily unarmed".

Location of the sunken Iranian warship off Sri Lanka. Graphics: AA

Iran reported on 8/3 that the sinking of the IRIS Dena resulted in the deaths of at least 104 crew members, with 32 injured individuals rescued by Sri Lanka.

In addition to the IRIS Dena, Iran sent two other warships, the IRIS Bushehr and IRIS Lavan, to participate in the naval exercise in India. After the Dena was sunk, these two ships sought refuge in ports in Sri Lanka and India.

Nhu Tam (According to Reuters, AP)