It is the third naval disaster for Iran in recent years – 19 sailors were killed in 2020 in a training exercise in the same area.
Iran’s largest navy warship has sunk in the Gulf of Oman after catching fire.
Iranian media did not give an explanation for the fire but said it had started at 2.25am local time on Wednesday.
Photos on social media showed sailors in life jackets evacuating the ship as it sank near the port of Jask, about 790 miles from the capital Tehran.
“All efforts to save the vessel were unsuccessful and it sank,” said Iran’s semi-official Fars news agency.
The ship was on a training mission, according to state TV.