It has been a day of violence and bloodshed in Tehran. An Iranian judge who jailed several dissidents has been shot dead in his car. The capital’s deputy prosecutor, Hassan Moghaddas, was gunned down by a lone assassin on a motorbike as he left the court building.In 2000 he had presided over the sentencing of seven people who had attended a Berlin conference on reform in Iran. The following year he sent journalist Akbar Ganji to jail for writing a string of articles linking officials to the murder of dissident intellectuals. Ganji is now in a critical condition after going on hunger strike. Earlier in the day, there was an explosion in an office building used by many foreign companies. A small bomb went off in a corrider outside the British Airways, BP and DaimlerChrysler bureaux, causing substantial damage. There were no casualties.