Tehran, Jul 12 (IANS): The Iranian Army has successfully completed three days of air defence exercises, where military units downed several mock pilotless aircraft, state-run Press TV reported.

Brigadier General Shahrokh Shahram, deputy commander of the army's Khatam al-Anbiya Air Defence Base, said air defence units in northwestern Iran effectively engaged the mock enemy's stealth, pilotless aircraft, "after detecting them electronically".

According to RIA Novosti, the exercise came in response to "the enemy's psychological warfare and is meant to neutralise the regional media's propaganda campaign against Iran", the army said.

Last week, the Islamic Revolution Guards Corps (IRGC) conducted a three-day missile exercise codenamed "Great Prophet 7". It tested Iran's newest surface-to-surface missile systems in the central province of Semnan.

An assortment of long, medium and short-range missiles targeted "aggressor airbases" in the Semnan desert, said Brigadier General Amir-Ali Hajizadeh, commander of the IRGC Aerospace Division.

Defence Minister Ahmad Vahidi has announced progress in the development and manufacture of an indigenous version of the advanced Russian S-300 air defence missile system.

The missile system called Bavar (Belief) 373 is said to be more powerful and more advanced than the Russian S-300.

An $800-million contract to supply Iran with the missile system was signed with Russian in 2007. Russia was to deliver five S-300PMU-1 battalions to Tehran, said RIA Novosti.

However, in September 2010, then Russian president Dmitry Medvedev signed a decree terminating the contract in line with UN Security Council resolution 1929 that bans supply to Iran of conventional weapons including missiles and missile systems, tanks, attack helicopters, warplanes and ships.