Supporters of a leading candidate in this month's presidential election in Iran have been arrested in Tehran, an aide to the candidate has said.

Hassan Rouhani was speaking to young followers during a campaign meeting in a mosque on Saturday when police picked up several supports and members of the campaign team of the the reformist candidate, his campaign manager, Mohammad Reza Nematzadeh, told the semi-official Mehr news agency.

"Some people were detained on the street after leaving the meeting, Nematzadeh told The Associated Press.

Rouhani is close to the ruling clerical elite and criticised the government of President Mahmoud Ahmadinejad during the first televised election debate on Friday.

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The June 14 election is to choose a replacement for Ahmadinejad, who cannot run for a third term.

Authorities have already pared down the list of candidates to eight, disqualifying Ahmadinejad's top aide and a former president who could have galvanised opposition to the clerical system.

On Sunday, after the arrests, a top official warned that Rouhani and others would be limited in their election drive.

"Police will confront individuals who have counter-revolutionary behavior" during campaigning, said the Iranian police chief, General Ismail Moghadam, according to the police website.

"It is natural that police have carried out their tasks."

An exile-based Iranian opposition website reported that authorities arrested at least seven people who attended Rouhani's campaign appearance.

It said the arrests were made after participants chanted slogans calling for the release of Mir Hossein Mousavi, an opposition leader and candidate in the disputed 2009 election that set off widespread riots when Ahmadinejad was re-elected.

Mousavi, and another reformist figure, Mehdi Karroubi, have been under house arrest for more than two years.

Source: Al Jazeera and agencies