Iranian army will start a naval drill in the country's southern waters on Friday, semi-official Fars news agency reported Tuesday. The six-day drill, to be held in Strait of Hormuz, Sea of Oman and northern Indian Ocean, will cover an area of one million square km, Iranian Navy Commander Rear Admiral Habibollah Sayyari was quoted as saying. In the drill dubbed Velayat 91, or Guardianship 91, defensive and missile systems, combat vessels and submarines will be tested, said the commander, adding that naval exercises to confront the enemy's threats and to enhance the battle preparedness are among the aims of the drill. On Dec. 24, 2011, Iran held the 10-day Velayat 90 naval drill in its southern waters, including the Persian Gulf, the Strait of Hormuz and the Sea of Oman, aiming at demonstrating the combat readiness and ability of the country's naval forces to defend its territorial waters. Iran has test-fired long and short-range missiles during the military drill in the Strait of Hormuz. Iran's submarines also hit pre-determined targets during the exercises, using domestically- manufactured torpedoes.