Iran's Revolutionary Guards said Friday that a ship was hit by an explosion after striking a mine in the Strait of Hormuz, where Tehran has sought to restrict navigation.
Since the outbreak of the Middle East war in late February, Tehran has insisted that vessels obtain its authorisation to traverse the strait and has attacked vessels that do not comply.
The United States has in response imposed a naval blockade on Iranian ports and provides military support to tankers using the vital trade route.
"A few hours ago, a ship carrying liquefied natural gas east of the Strait of Hormuz tried to cross an unauthorised passageway south of the strait, but was hit by a naval mine and exploded violently," the Guards said on Friday.
They did not give the name or origin of the vessel.
In recent weeks, Iran's armed forces have repeatedly reported fires or explosions on board ships in the strait, often saying the vessels struck mines.
The US military, however, claims to have cleared the main routes through the waterway of mines.
The Revolutionary Guards, the ideological arm of Iran's military, also said overnight that their forces had targeted a US early warning radar system in Bahrain, a US ally in the Gulf that is home to American military installations.
The attack was not confirmed by either the US or Bahrain.
