The Iranian army says a missile strike on a naval vessel taking part in an exercise in the Gulf of Oman has killed 19 sailors and wounded 15.
The statement drastically raised the death toll in the incident, which happened on Sunday.
Earlier Iranian state media reports said the Konarak, a Hendijan-class support ship, was too close to a target during an exercise.
The vessel had been putting targets out for other ships to target. It said the missile struck the vessel accidentally.
The friendly fire incident happened near the port of Jask, some 790 miles south-east of Tehran, in the Gulf of Oman, state TV said.
A local hospital admitted 12 sailors and treated another three with slight wounds, the state-run IRNA news agency reported.
Iranian media said the Konarak had been overhauled in 2018 and was able to launch sea and anti-ship missiles. The Dutch-made vessel was in service since 1988 and had capacity of 40 tonnes. It usually carries a crew of 20 sailors.
Iranian media rarely report on mishaps during its exercises, signalling the severity of the incident. This incident also comes amid months of heightened tensions between Iran and the US since President Donald Trump unilaterally withdrew from Tehran’s nuclear deal with world powers in 2018 and imposed crushing sanctions on the country.