One Iranian website said it was a homemade grenade -- a report at first confirmed by a source in Ahmadinejad's office.
But as the motorcade moved on and as the uninjured president made no mention of an attack, the event was soon re-written by Iran's official state media, reports CBS News correspondent Mark Phillips
Iran hasthat Ahmadinejad's convoy was attacked by a grenade. The president's media office stated that a firecracker was set off within a distance of 500 meters from Ahmadinejad's motorcade.
"Ahmadinejad is trying to downplay the threat to him," said CBS News security analyst Juan Zarate. "The threat to the regime may signal the fact that he actually does feel there is a threat."
The crackdown on the opposition in Iran may now be more subtle than it was in the days following the disputed election in June 2009, but there is still plenty of discontent, despite Ahmadinejad's claim in a CBS interview last week that he speaks for all of Iran.
"What I say is what the Iranian people say," he stated. "I cannot say anything that is not the will of the Iranian people."
Ahmadinejad had recently accused Israel of plotting to assasinate him.
Today's incident may show he has other, internal enemies as well.