Iran has tested what it says is the world's fastest underwater missile, designed to elude radar and destroy enemy submarines.
The missile was fired from a boat into the Gulf towards a target
National TV programmes were interrupted to show footage of the missile being fired into the Gulf and destroying a derelict ship.
The test came two days after it tested a conventional missile capable of being equipped with multiple warheads.
Both tests come amid rising tensions over Iran's nuclear ambitions.
Iran's elite Revolutionary Guard troops are carrying out a series of military exercises and tests in the Gulf and in the Arabian Sea.
The new missile, called Hoot, or Whale, could be deployed on Iranian ships in the oil-rich area, which is home to the US 5th Fleet.
Iranian military chiefs said the new missile would be fired from ships with technology to avoid radar detection.
It is said to travel at 360km/h (233mph), three to four times faster than most conventional torpedos.
"It has a very powerful warhead designed to hit big submarines," Gen Ali Fadavi," deputy head of the Revolutionary Guard, told the Associated Press.
"Even if enemy warship sensors identify the missile, no warship can escape from this missile because of its high speed."
Friday's test demonstrated the Fajr-3 missile, also designed to escape radar and capable of hitting several targets with multiple warheads.
The United Nations Security Council has demanded Iran stop enriching uranium, which Tehran insists is part of a civilian nuclear energy programme.
The US says Iran is aiming to develop nuclear weapons, and is seeking sanctions.