Iranian authorities have threatened tougher action on protesters after tens of thousands marched at universities across the country in the biggest anti-government rallies since the disputed June elections. Dozens of people are reported to have been arrested after violent confrontations. Foreign journalists were banned from reporting on the rallies, and the Iranian authorities closed down mobile phone networks and severely restricted internet access. According to The Times dozens of government agents on motorbikes have surrounded the Tehran office of Mir Hossein Mousavi, the opposition leader, to prevent him attending rallies and the country’s chief prosecutor is threatening to arrest him.  Read more here