Iran's armed forces will begin three days of war games on Monday involving anti-aircraft defence systems, Iranian media said.

The exercises will be held amid persistent speculation about a possible US or Israeli strike on Iran's nuclear facilities, which the West and Israel say are part of a clandestine bid to build atomic bombs, despite Tehran's denials.

The ISNA news agency said both Iran's Revolutionary Guards and its regular army would take part in the drills.

'Manoeuvres with the participation of anti-aircraft defence systems will be held for three days starting Monday,' it said, without giving further details.

The English-language Iran Daily said the aim was to maintain and upgrade the combat readiness of relevant units as well as to 'test new weapons and defence plans.'    

Speculation about a possible attack on Iran's nuclear facilities has risen since Israel staged an air force exercise in June which was reported to be a simulation of a strike against Iran. Iran says it would hit back if attacked.

An Iranian commander last week said the Iranian air force would hold exercises during Ramadan, which began in Iran on Sept. 2, but it was not immediately clear whether he was referring to the same drills as the ISNA report.

Alongside the regular army, Iran has a Revolutionary Guards force viewed as guardians of the Islamic ruling system. The Guards have a separate command and their own air, sea and land units, but often work with the regular military.

Iran has dismissed reports of possible US or Israeli plans to strike Iran, but says it would respond by attacking US interests and Israel if any such assault was made.

Iran's Foreign Ministry spokesman last week denied reports, based on comments from Israeli defence sources, that Iran had bought Russia's advanced S-300 anti-aircraft missile system and would get it this year.

There have been conflicting reports about whether Iran was buying the S-300 system. Defence Minister Mostafa Mohammad Najjar said last year Russia had agreed to deliver the missiles to Iran under a signed contract. Russia denied such plans.

Iran, the world's fourth largest oil producer, says its nuclear programme is aimed at making electricity, not bombs. The United States says it wants diplomacy to end the row but has not ruled out military action if that fails. - Reuters