The state of emergency hands responsibility for security in the capital to the Chilean military.
Protests began October 11 as students jumped turnstiles and clashed with police in mass fare evasion to protest fare hikes.
In Manhattan, mourners released white balloons in Manuel José Núñez' memory, lighting candles and laying flowers beside photos of the 28-year-old.
Deadly rainstorms have polluted the Maipo river in Santiago.
Orlando Letelier was assassinated by a car bomb in 1976.