TEHRAN — Iranian President Mahmoud Ahmadinejad was unhurt on Wednesday after an explosive device, officially described as a firecracker, went off near his motorcade.

Ahmadinejad was on his way to a sports arena to make a speech in Hamedan, south of the capital, when the explosion occurred.

Conservative website Khabaronline, the first source to report the incident, initially said a hand grenade was thrown at the hardliner’s motorcade but later in the day dropped “grenade” in its report and used the word “firecracker” instead.

“This morning a hand grenade exploded next to a vehicle carrying reporters accompanying the president,” the website, close to parliament speaker Ali Larijani, said first.

“Ahmadinejad’s car was 100 meters away and he was not hurt,” it said, adding that the alleged attacker was detained.

Iran’s Mehr news agency quoted witnesses as saying a “hand-made noise bomb exploded a far distance from the president’s car.”

“Nobody was hurt and several people have been arrested,” it said.

Ahmadinejad later delivered his speech and made no reference to the incident.

An official in the president’s media office told AFP the explosion was from a “firecracker.”

The ISNA and ILNA news agencies also said the blast was caused by a “firecracker,” while Fars news agency said a “hand-made grenade” had been thrown at the motorcade.