Tens of thousands swelled into Cairo\'s Tahrir Square on Tuesday, intensifying the pressure on Egypt\'s military leaders to hand over power to a civilian government. Clashes between protesters and riot police continued for a fourth night in and around the square. Security forces retaliated by firing teargas at the protesters. The new wave of protests and violence around the country has left 29 dead, and has thrown Egypt\'s politics into chaos less than a week before landmark parliamentary elections are to begin.