Iran\'s Army and the Islamic Revolution Guards Corps (IRGC) have test-fired a range of missiles and unveiled their military achievements in the ongoing joint air defense drill starting on Monday. Code-named \"Modafe\' an-e Aseman-e Velayat 4\", or \"The Defenders of the Sky of Guardianship 4\", the seven-day drill is held in an area of more than 850,000 square km, accounting for half of the country, in which a large number of soldiers are participating. On Wednesday, the third day of the drill, Iran testified S-200 air defense missile system \"successfully\" in the southern port city of Bandar Abbas, said the commander of Iranian Khatam al- Anbia Air Defense Base, Farzad Esmaili, adding that the missile system has been developed for high-altitude targets. The missile system can also confront strategic aircraft and semi-ballistic missiles, Esmaili was quoted as saying. In July, 2011, IRGC said Iran had managed to upgrade the Russian-made long-range S-200 air defense system into an entirely new apparatus, according to local media. Also on Wednesday, Iranian air force \"successfully\" test-fired another two homemade missile systems, \"Qader\" and \"Ya-Zahra 3\", in the eastern province of Southern Khorasan, the official IRNA news agency reported. The \"Qader\" missile is equipped with electro-optic and laser rangefinder systems, while the \"Ya-Zahra 3\" missile is designed to be used in low altitudes, said the report. On Tuesday, semi-official Fars news agency reported that Iran \" successfully\" test-fired the Hawk air defense system. The state- run IRIB TV also showed a footage in which the missiles mounted on a lorry and was fired at an aircraft. One day earlier, Iranian Defense Minister Brigadier General Ahmad Vahidi unveiled a home-made hovercraft that can launch missiles and serve as a launch pad for drones, Fars reported. The hovercraft was designed and developed by Iranian experts in two models for combat, \"Tondar\" and \"Thunderbolt\", and for transportation missions, said the report. Vahidi said \"Tondar\" can be equipped with different types of weapons produced by the Iranian defense industries, including rockets, guns and unmanned aerial vehicles. \"Thunderbolt\" can be used \"for coastal patrolling, for offensive reconnaissance operations, for mid-range amphibious missions and asymmetric defense, as a personnel and equipment carrier for logistical support for islands and coastal areas, as a command vessel, or as a sea ambulance for relief and rescue missions,\" he was quoted as saying. He further added that the new hovercraft will increase the combat and reconnaissance capabilities as well as the mobility of the Iranian armed forces. Press TV reported Monday that besides radar air defense and missile systems, as well as tapping, artillery and surveillance systems, diverse kinds of fighter jets, including F-4, F-5, F-7, F- 14, Mirage and Sukhoi, as well as refueling aircraft would also be deployed in the drill. The military units would also practice modern tactics in response to recent threats from certain parts of the world, Esmaili said Monday. Esmaili said the ongoing drill displays the full strength and preparedness of Iran\'s air defense forces to defend the Islamic republic\'s interests, and the message sent by the drill is \"peace\" for the regional and friendly countries and \"a strong slap\" at the enemies. Iran has held a series of \"Modafe\' an-e Aseman-e Velayat\" drills since years ago, aiming to prepare its air defense forces in the face of Western threats against the country\'s nuclear sites. The United States and its Western allies suspect that the nuclear activities of the Islamic republic may aim at weapon-grade program, while Iran insists on its \"peaceful\" nature. The United States and Israel have not ruled out the possibility of striking Iran\'s nuclear establishment. Deputy Commander of Iran\'s Armed Forces Chiefs of Staff Brigadier General Masoud Jazayeri said Wednesday that the Islamic republic\'s armed forces hold a \"doctrine\" that \"we should respond to any threat immediately in proportion to the type of the threat. \" \"Necessary preparations are in place for this measure, meaning that the Islamic republic of Iran\'s Army and the IRGC possess the necessary and sufficient preparedness for the implementation of the doctrine,\" Jazayeri was quoted by Press TV as saying. He said a lot of training has taken place in this regard, especially concerning the defense of the Persian Gulf and the Strait of Hormuz.