An informed source in Iran's presidential office has rejected as "false reports" of grenade attack on Iranian President Mahmoud Ahmadinejad, local English channel Press TV reported on Wednesday.

Several foreign and local media reports said earlier that a grenade exploded near the convoy of Ahmadinejad during his provincial visit to the western city of Hamedan on Wednesday while the president escaped unhurt.

"No such attack took place," the state-run television quoted the unnamed source as saying.

Meanwhile, Press TV reported from Hamedan that the blast was a "firecracker" and it is something customary to use firecrackers in the region for the welcoming ceremonies.

Conservative Iranian website khabaronline.ir reported on Wednesday that the explosion took place in Hamedan as the president was going to make a public speech. The report said a man suspected of throwing the grenade was detained.

The website said the attacked car was a mini-bus which was carrying correspondents who had come to Hamedan with the president on Wednesday morning.

The report said that no casualties have been reported till now.

"The car of the president was 100 meters ahead of the blast and nothing happened to him," the report said.

Since 2005 when Ahmadinejad took office, his administration has started a series of provincial tours nationwide in a bid to listen to the problems of local officials and people and to develop and launch several social and economic projects for those provinces.