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Iran has been displaying its military power at a ceremony to mark the country's annual army day.
Speaking at the parade, President Mahmoud Ahmadinejad said Iran was the most powerful nation in the world.
The country's strength was such that no major power would dare to challenge its security, he said.
Official media claimed the ceremony included the largest ever show of aerial strength, with a fly past by almost 200 aircraft.
There was also a huge military parade, with missiles displayed on trucks.
Top officials have made much of Iran's achievements in being able to maintain and manufacture sophisticated military aircraft or other equipment despite US sanctions against it.
President Ahmadinejad expressed his confidence in the strength of the country's armed forces.
He said Iran was now so powerful that "none of the current world powers are capable of, and have the courage to, threaten the Iranian nation and its interests and security".
The president stressed that Iran's armed forces were purely defensive, but warned that they would respond strongly to any act of aggression.
The parade comes amid continuing tension between Iran and the West over Tehran's controversial nuclear programme.
It also follows a recent war of words between Iran and Israel, in which an Iranian deputy army commander said that if Israel attacked Iran, it would be eliminated from the global arena.