A Russian news report says a high-speed torpedo unveiled by Iran early this week during war games in the Persian Gulf appears to be based on Soviet and Russian design.

The daily Izvestia newspaper says the torpedo closely resembles Russia's (VA-111) Shkval, which can reach speeds of 360 kilometers per hour - about four times the speed of a conventional torpedo.  The Shkval has an estimated range of seven kilometers.

The newspaper says the Russian model was first developed in the 1960s and can carry a nuclear warhead.  It also says an underwater rocket comparable to the Shkval would let Iran control access to the Gulf.

Early Tuesday, Iran said it had successfully test-fired a new land-to-sea missile.

Iranian media say the latest test involved the medium-range Kowsar missile, which can evade radar detection and foil jamming systems.

Iran has announced four successful test-firings since it began war games on Friday.

The U.S. Defense Department says Iran has probably made advances in its missile technology.  But pokesman Bryan Whitman also says Tehran has been known to "boast and exaggerate" in statements about its technical and tactical capabilities.

Some information for this report was provided by AFP, AP and Reuters.