Iran has denied reports of a bomb attack on the motorcade of President Mahmoud Ahmadinejad.
A source in the president's office said President Ahmadinejad had survived the attack with a homemade explosive device during a visit to the western city of Hamadan.
The source said Mr Ahmadinejad's convoy was targeted as he was travelling from Hamadan's airport to give a speech in a local sports arena.
It was reported that others were injured in the blast.
One person has been arrested and the president was unhurt, the source said.
There was no immediate claim of responsibility for the attack.
Al-Arabiya television said an attacker had thrown a bomb at Mr Ahmadinejad's convoy before being detained.
Dubai-based Al Arabiya television cited its own sources as saying the bomb had hit a car carrying journalists and presidential staff.
Mr Ahmadinejad later appeared on live Iranian television at a sports stadium in Hamadan.
He was apparently well and made no mention of any assault.