Iranian President Mahmoud Ahmadinejad survived an attack with a homemade explosive device on his motorcade during a visit to the western city of Hamadan on Wednesday, a source in his office said.
The source said Ahmadinejad's convoy was targeted as he was traveling from Hamadan's airport to give a speech in a local sports arena and the president was unhurt but others had been injured in the blast.
One person had been arrested, the presidency source said. There was no immediate claim of responsibility for the attack.
The populist, hard-line Ahmadinejad has accumulated enemies in conservative and reformist circles in the Islamic Republic as well as abroad.
Al Arabiya television said an attacker had thrown a bomb at 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.
Ahmadinejad appeared on live Iranian television at a sports stadium in Hamadan. He was apparently well and made no mention of any assault.
During a speech to a conference of expatriate Iranians in Tehran on Monday, Ahmadinejad said he believed he was the target of an assassination plot by Israel. "The stupid Zionists have hired mercenaries to assassinate me," he said.
The oil market initially reacted calmly to reports of the attempted attack.
One energy analyst said: "People are just waiting to see what this is about – to confirm the nature of the action."
Ahmadinejad recently sought to isolate rival political factions by declaring that "the regime has only one party, which is the velayat" — a reference to Shi'ite Islam's hidden Imam, for now represented by Supreme Leader Ayatollah Ali Khamenei.
One of Ahmadinejad's trademarks has been constant travel around his vast country to deliver provocative speeches before outwardly adoring crowds who shout "death" to Iran's foes.