According to the agency, Karroubi’s presence at the service prompted a number of people there to seek to have him removed from the mosque by force, but they were prevented from doing so by the cleric’s bodyguards.
The report said the bodyguards fired tear gas and also threatened to “use arms” against the assailants.
Karroubi, a former parliament speaker who has twice run unsuccessfully against President Mahmoud Ahmadinejad for the post, was later confronted by “angry” people outside the mosque as he was leaving the compound, Fars said.
It said his bodyguards again used tear gas and also “fired shots into the air” to disperse the crowd so they could remove him from the area, the report said.
The report was not immediately confirmed by other media or Karroubi’s website.
Following the disputed presidential election in 2009, Karroubi, along with Mir Hossein Mousavi, emerged as the leader of popular street protests that called the vote fraudulent and demanded a recount.
The two and some of their relatives have been subjected to repeated physical aggression and intimidation by pro-government militants over the past year.
