DUBAI - Iranian authorities arrested five social media users on security charges, a judiciary spokesman was quoted as saying on Monday, in the latest incident in the establishment's long fight to suppress online dissenters. 'Several members of a group which systematically took steps against security and called for illegal activities on social media were identified and arrested by the security forces,' Gholamhossein Mohseni-Ejei was quoted as saying by the Mehr agency. He said five people had been arrested so far and more may follow as part of the same operation.