Tens of thousands of protesters in Chile staged a "Super Monday" mega-rally to kick off the third week of anti-government protests that have sparked deadly unrest.
Scattered clashes broke out with police firing water cannons and tear gas as protesters faced off against them in the streets of the capital Santiago.
Protesters angry at high costs and tight pensions are demanding the resignation of conservative President Sebastian Pinera.
Pinera held talks with opposition parties last week but they said he failed to convince them he has the will to make the necessary changes to calm the protests.
Prosecutors say 20 people have died in clashes since the protests began on October 20.
A UN human rights mission is investigating allegations of police brutality.
Pinera tried to crack down on the riots in the first week but the bid backfired.
He was forced to cancel the hosting of two major international summits including the COP climate meeting due to the unrest.
Protesters organized rallies on Monday under the slogan "This is not over."
Some citizens returned to work despite vandalism that has damaged the underground train network.
"The fight goes on, but we have to get the country up and running again," said one commuter, accountant Olga Perez.
"It won't help anyone if the country falls into a slump."
Protesters are calling for constitutional reform. Chile's current constitution dates back to the 1973-1990 dictatorship of Augusto Pinochet.
A survey by pollster Cadem published on Sunday indicated that 87 percent of Chileans favored such reforms.
The study indicated Pinera's approval rating had plunged to 13 percent.
The government said Chile's economy grew three percent in September but it forecast a contraction of 0.5 percent in October due to the unrest.