Chilean police arrested 19 people on Tuesday after clashing with Mapuche Indians outside a court in the southern city of Collipulli, which has been hit by a string of arson attacks.
The clashes began when about a dozen people threw rocks at police cars.
Fernando Millacheo, a member of the Mapuche indigenous community, was to appear there to answer charges of robbery, arson and attempted murder.
Mr Millacheo denies the charges and is on the 51st day of a hunger strike in protest against his arrest. Police said they had arrested nine women and 11 men.
Three officers and five Mapuches were lightly injured.
Riot police continued to stand guard in the late afternoon outside the court in Collipulli, a city in the Araucania region that Chile's largest indigenous group insists is its usurped ancestral land.
The Mapuche, which means "people of the land" in their native Mapudungun language, resisted the Spanish conquest for 300 years and their desire for autonomy remains strong.
Many of the million Mapuche among Chile's 16.5m people still live in Araucania, most in poverty.
A radical faction of the Mapuche have occupied and burned forestry farms and lorries to demand the return of ancestral territories.
Police have also been accused of violent abuses, including storming into Mapuche homes and hurting women and children by shooting rubber bullets and tear gas during demonstrations.
If you appreciated this article then please consider donating to the Morning Star's Fighting Fund to ensure we can keep developing your paper.
Donate to the Fighting Fund here
Defence Secretary Philip Hammond believes himself vindicated by the High Court ruling that his Iraq Historic Allegations Team (IHAT) is independent.
A look at the causes and possible outcomes of Silvio Berlusconi and his right-wing coalition's lead in the polls.
Attacks such as yesterday's horrific murder in Woolwich didn't happen before the 'war on terror.' It's time we recognised the consequences of the conflicts we've unleashed