BEIRUT (Reuters) - Iran's rulers are tensing for a new trial of strength with protesters on Sunday, when an emotive Shi'ite ritual coincides with seventh-day mourning for a defiant ayatollah who was once a heartbeat from the pinnacle of power.
A loose reformist opposition movement that swelled after a disputed presidential election in June is exploiting the rhythms of the Islamic Republic's political-religious calendar to stage rolling protests and sustain the momentum of its struggle.
