"Three people died in a fire at a supermarket, two of them burned and one was taken to a hospital where he died," said Mayor Marla Rubilar.
Chileans, angry at the worsening social and economic situation in the country, clashed with security forces for a second day on Saturday, despite a declared state of emergency to halt the worst violence in Latin America's most stable country.
Witnesses reported the burning of five buses in the city center, and the authorities decided during the day to stop the bus traffic completely.
The protests began after the announcement of an increase in the price of metro tickets from 800 to 830 pesos (about 1.40 euros), but later expanded to include other topics, including the economic model adopted and the provision of health services and education, which remains almost exclusively the private sector.
Pinheira announced on Saturday that his decision had been suspended, and later the general appointed to ensure security in the capital imposed a total curfew in Santiago in response to the "abuses that have occurred today."