Thousands of demonstrators poured into the streets of Santiago de Chile on Sunday to honour the victims of General Augusto Pinochet's dictatorship, in a march that started peacefully but ended in violence.
Although it has been 46 years since the military coup that brought Pinochet to power, his memory still divides Chileans.
The protest began in central Santiago, with many demonstrators carrying red carnations and holding photos of loved ones who were killed or disappeared during the Pinochet years.
Police at first protectively lined the route as marchers proceeded to a memorial to Pinochet's victims at the city's General Cemetery.
But pitched battles broke out at the cemetery's entrance, with protesters hurling stones and police responding with tear gas and water cannon.
There were several arrests, but no immediate reports of injuries.
Police confirmed that 4,000 people attended the march, and 23 were detained, while organizers estimated that there were 20,000 attendees.
The memorial honors the estimated 3,000 victims - the dead and the disappeared - of the 17-year Pinochet dictatorship (1973-1990).
Under the slogan For Truth and Justice, the Communist Party and several other leftist organizations demanded progress in investigations of hundreds of unresolved human rights cases.
Of the nearly 1,200 people listed as missing since the Pinochet era, barely more than 100 cases have been located. Many people were thrown into the sea or had their bodies dynamited as the Pinochet regime worked to erase evidence of its crimes.
On Saturday, Communist deputy and human rights activist Carmen Hertz announced that years after her husband Carlos Berger disappeared, she had recovered some of his remains. Berger was detained and shot during the Pinochet era.
The desert returned to us pieces of his back and his jaw, Hertz wrote in a grim post on Twitter, adding that his murderers have enjoyed decades of impunity