TEHERAN– Iran's official news agency said Wednesday that an explosion near the President Mahmoud Ahmadinejad's convoy was just an excited fan setting off fireworks, denying earlier reports of an assassination attempt.A fan set off a firecracker similar to those used during sports matches to express his excitement at the president's visit to the western Iranian town of Hamedan, reported the IRNA news agency. The explosion near the president's convoy had set off a flurry of media reports, including one that it was a handmade grenade.RELATED:Iran opposition warns of revolutionIran blames US for suicide bombingThe conservative Iranian website, khabaronline.ir, said a grenade exploded as the president's convoy headed from the airport to the venue for the speech, but did not harm him.Ahmadinejad went on to give his speech as planned, and it was broadcast live on state television. He made no mention of the attack in his remarks, focusing instead on the country's disputed nuclear program.He struck a hard line against Western demands that Iran halt its nuclear activities. "It will be one of your big mistakes if you think you, resorting to lies and hue and cry, are able to achieve something and we will give you any concession," Ahmadinejad told the crowd at the Hamedan stadium. One person was arrested in connection with the attack, the website report said, adding that Ahmadinejad's car was about 100 yards (meters) from the blast. It also said there was no information whether anyone was injured."The explosion caused a lot of smoke," the report said.Ahmadinejad, whose popularity at home is waning amid a faltering economy and tightened UN and Western sanctions over Teheran's nuclear program, regularly tours the countryside to deliver speeches to grass-roots supporters in cities and town across Iran.A US-Iran relations specialist, Jim Walsh with the MIT program on security studies, said that "Iran has a strong interest in trying to minimize this event, given the domestic problems following last year's unrest over the presidential election." Walsh stressed that assassinations have been a staple of Iranian politics in the past and that while there have been attempts on other Iranian officials, there's been no known such attack on Ahmadinejad.Several media outlets differed in details of what happenedThe semi-official Fars news agency said a handmade grenade was thrown at the path where the president and his entourage had been but only after they had left the site. Fars said the explosion disturbed people at the site. The government-owned Borna news agency said somebody threw a firecracker after the convoy had passed, while the semiofficial Mehr news agency called it a handmade percussion grenade.A photo by the semiofficial ISNA news agency showed smoke dozens of yards away from the convoy, which was surrounded by people. It did not elaborate on the source of the smoke.The report from IRNA quoted an official in the governor's office saying the "firecracker did not hurt anyone and did no damage." Hamedan, 200 miles (340 kilometers) west of Tehran, is not known as a restive area, but it is close to Kurdish area of Iran that has witnessed occasional clashes between Kurdish rebels and security forces over the past years.