The Guards had conducted exercises in the Gulf and the Strait of Hormuz between April 22 and 25. State media said they tested missiles and a new speedboat.

Iran has warned that it will close the strait if it is attacked. Roughly 40 per cent of the world's oil supplies pass through the strait each day.

five-day exercise in Novemberdemonstrated the defences around Iran's nuclear facilities.

The Iranian military also recently unveiled a new air defence system, the S-200, during last month's Army Day parade in Tehran.

Iran wants to buy a more advanced S-300 system from Russia, and signed a $730m contract in 2007 to buy the missiles. But Moscow, under pressure from the US and Israel, has repeatedly delayed the deal.