Five people died Sunday when a garment factory was torched by looters near Chile's capital Santiago, bringing the death toll in a wave of unrest to seven as authorities expanded a state of emergency.
Police and the military fired tear gas and used water cannon against protesters in the city as clashes over price hikes and social inequality raged through a third day.
Almost all public transport was paralyzed in Santiago, with shops shuttered and many flights cancelled at the international airport, leaving thousands of people stranded and unable to leave due to the curfew.
After an emergency meeting late Sunday, president Sebastian Pinera defended his decision to call a state of emergency and deploy troops onto the streets for the first time since Augusto Pinochet's military dictatorship between 1974-1990.
"Democracy not only has the right, it has the obligation to defend itself using all the instruments that democracy itself provides, and the rule of law to combat those who want to destroy it," Pinera said.
The state of emergency was extended on Sunday, with Interior and Security Minister Andres Chadwick saying new decrees were being drawn up for Antofagasta in the north, Valdivia in the south, and other cities such as Valparaiso, Temuco and Punto Arenas.
Firefighters said five people died in a garment factory burned by rioters in Renca, a northern suburb of Santiago.
Earlier, Chadwick said two women burned to death after a store owned by US retail chain Walmart was set alight in the early hours of Sunday.
One victim, who authorities initially said had died in hospital, suffered burns on 75 per cent of her body.
Authorities reported 103 serious incidents throughout the country with 1,462 people detained -- 614 in Santiago and 848 in the rest of the country.
Protesters set fire to buses, smashed up metro stations, knocked down traffic lights, ransacked shops and clashed with riot police in Santiago and other cities.
During the curfew from 7:00 pm (2200 GMT) until dawn, people should "be calm and all in their homes," defence official General Javier Iturriaga announced.
What started earlier in the week as a protest against a hike in metro fares escalated dramatically on Friday as demonstrators expressed anger over social inequality and the government's liberal economic system.
On Saturday, Pinera announced he was suspending the fare increase.
Pinera acknowledged that those in the streets had "good reasons" to protest but called on them "to demonstrate peacefully."
The appeal failed to prevent further rioting and looting.
"It's really sad what's happening, but the people are outraged because they're not being listened to," 26-year-old Antonia told AFP in central Santiago.
Dozens of protesters torched a building belonging to Chile's oldest newspaper, El Mercurio, in Valparaiso on Saturday evening, while elsewhere a metro station, supermarkets and other stores were set on fire.
Social tensions erupt
Santiago's metro system -- South America's largest and most modern and used by around three million people a day -- was shut down on Friday as protesters burned and vandalized stations.
Louis de Grange, president of the state Metro SA company, told Canal 13 the "brutal destruction" of the service had caused more than $300 million in damage.
The hike in fares that set off the violence would have raised the price of peak hour travel from 800 to 830 pesos ($1.13 to $1.15).
The government said the hike, which followed a 20-peso increase in January, was driven by rising oil prices and a weakening peso.
Initially, students and others responded by fare-dodging, but underlying social tensions quickly bubbled to the surface.
On Friday, the headquarters of the ENEL Chile power company and a Banco Chile branch -- both in the centre of Santiago -- were set on fire and heavily damaged.
Chile has the highest per capita income of Latin America at $20,000, with expected economic growth this year of 2.5 per cent and just two per cent inflation.
But there is widespread frustration with economic policies that have virtually privatized all health care and education, at a time that falling pensions and rising costs of basic services have exacerbated social inequality.