Iranian Navy forces test-fired short-range and medium-range missiles as well as torpedoes " successfully" in ongoing naval drill on Monday.

On the forth day of a six-day massive naval drill dubbed Velayat 91, or Guardianship 91, which started on Friday in Iran's southern waters, Iranian Navy "successfully" test-fired the latest version of the home-made surface-to-air Ra'd (Thunder) missile, Press TV on Monday cited an official as saying.

The spokesman for the drill, Rear Admiral Amir Rastegari, said the earlier version of Ra'd missile had been modified by Iranian Navy experts and installed on warships.

The new Ra'd missile could strike medium-range aerial targets, Rastegari said Friday.

The Iranian Navy also "successfully" launched its indigenous short-range cruise missile dubbed Nasr ( Victory) on the fourth day of the major military exercises, according to Press TV.

Nasr cruise missile, which can destroy vessels of up to 3,000 tons, can be launched from both inland bases and offshore military vessels, Iranian Defense Minister Ahmad Vahidi was quoted as saying.

Vahidi reiterated that new features will be added to the missile in the near future so that it can also be launched from helicopters and submarines.

Besides, Iran's Navy test-fired state-of-the-art torpedoes by hitting and destroying targets during the fourth day of its naval drill, Press TV reported.

Rastegari said "following successful coastal defense and the retreat of the (hypothetical) enemy's vessels," Iranian sub- surface vessels ambushed the mock enemy forces and destroyed them with advanced torpedoes.

He said that Iran's surface units chased the enemy's vessels while launching heavy missile attacks against the hostile forces, according to the report.

Meanwhile, Iran's naval units on Monday exercised shooting down hypothetical enemy aircrafts, specially Unmanned Aerial Vehicles ( UAVs), during the drill underway in the country's southern waters, semi-official Fars news agency reported.

"Today, enemy drones came under the heavy fire of the (Iranian) courageous naval forces in both the sea and on the coasts before they could infiltrate the positions of the friendly troops and finally they were hit and destroyed by Misaq shoulder-launched missiles," Rastegari was quoted as saying.

Rastegari also said that friendly reconnaissance and combat drones also penetrated the positions of the enemy forces in separate missions and targeted their vessels after gathering intelligence in their reconnaissance missions, according to Fars.

On Sunday, Commander of Iranian Navy's Aviation Unit Rear Admiral Alireza Nayyeri said that the Iranian Navy has boosted and upgraded the capability of its home-made UAVs.

"The UAVs owned by the Navy have been manufactured by the Army and the Armed Forces' experts based on the latest technologies," Nayyeri was quoted as saying.

Iranian commanders have said that the ongoing maneuver sends a message to enemies that Iran will seriously defends its vital interests in all areas, in particular in international waters.

The naval drills, by the Islamic republic, is being carried out in the Strait of Hormuz, the Sea of Oman, the north of the Indian Ocean, the Gulf of Aden and the Bab-el-Mandeb Strait.