A submarine battery exploded in an Iranian military shipyard on Saturday, killing three workers, state broadcaster IRIB said.
"Three Defence Ministry staff were martyred after a submarine battery exploded at the Shahid Darvishi shipyard in (the Gulf port of) Bandar Abbas..., which builds and repairs military ships and submarines," IRIB said on its website.
Iran has developed a large domestic arms industry after decades of international pressure and despite embargoes that have barred it from importing many weapons.