According to fliers circulating on social media, 18 protests were planned for urban centers around Chile in the late afternoon, with more planned outside Chilean embassies abroad.
The father of Camilo Catrillanca, a Mapuche man from the southern Araucania region which has long been in conflict with the state, appealed to people to demonstrate "calmly." "We don't want to mourn the death of any young person, whether Mapuche or from elsewhere, because for us it would be to relive the pain again," he told local radio station Cooperativa.
Camilo Catrillanca, the grandson of an indigenous leader, was shot in the head in November 2018 in a police operation in a rural community near the town of Ercilla, 480 miles (772 km) south of Santiago.
The incident - and subsequent accusations of cover-up - triggered huge protests throughout Chile.
Four police offers are due to go on trial on charges of homicide and obstruction of justice later this month.
Thursday's protests follow on from four weeks of intense unrest that started over a hike in public transport fares but have broadened to encompass grievances over low wages, the high cost of living and social inequality.