Dozens are feared after an Iranian destroyer accidentally sunk one of his own warships in a friendly fire accident, according to reports.
The Iranian Navy reported one dead and several injured in a naval exercise, it is believed.
However, about 40 navy personnel went missing after the sinking, local media have claimed.
The incident happened on the Konarak ship, news agency Fars said.
Unconfirmed social media reports claimed that dozens had been killed in the exercise during a friendly fire incident.
Local media have said the battleship was accidentally hit by a C-802 Noor missile from Iran’s Jamaran frigate in the Gulf of Oman, causing it to sink.
Video footage claims to depict the moments when a fisherman recovered injured sailors from the sea.
The Jamaran frigate entered service in October 2018.
Last month, Donald Trump ordered the US Navy to shoot down all Iranian gunboats that “harass” US ships.
It came after 11 ships of the Iranian Islamic Revolutionary Guards Navy (IRGCN) came dangerously close to US ships in the Gulf earlier in April.
In January, Iran was forced to admit that its army had accidentally shot down a Ukrainian passenger plane, killing all 176 on board.
Tehran initially claimed that the aircraft had had a technical problem and that the crash was an accident, and quickly removed the wreck from the farmland site.
But, as Western intelligence agencies said Ukrainian International Airlines Flight 752 was hit by a missile, Iran was later forced to admit that it “accidentally” shot down the plane.
Four British soldiers were killed when the plane crashed shortly after taking off from Tehran airport on its way to Kiev on January 8.
Hours earlier, Iran had launched ballistic missiles at Iraqi bases that house American forces in retaliation for the American assassination of Iranian General Qasem Soleimani during a drone attack on January 3 in Baghdad.
Tensions between Tehran and Washington have intensified since 2018, when the United States withdrew from Iran’s nuclear pact with world powers and re-imposed sanctions, erupting in brutal military strikes this month.