Thousands of Chileans took to the streets in a march to remember those abducted and killed in the coup that brought Augusto Pinochet to power, almost 39 years after the turmoil.
Police used water cannons and tear gas to disperse the crowd after some marchers threw stones at government buildings and destroyed some traffic lights on Sunday.
Many demonstrators waved Chilean and Communist Party flags, or carried family photos of beloved kin who went missing and were killed in the Cold War-era bloodshed.
Pinochet, who ruled Chile from 1973 to 1990, came to power in a military coup that toppled elected socialist president Salvador Allende on September 11, 1973.
His dictatorship caused the death or disappearance of more than 3,200 people, and another 37,000 people were imprisoned and tortured during the general's 17-year rule, according to human rights organisations.
Pinochet died in 2006 without ever having been convicted of crimes committed during his regime.
The head of the Association of Relatives of Disappeared Detainees described the administration of Chilean President Sebastian Pinera as "the same repressive right-wing as the dictatorship".