Tens of thousands of Chileans gathered in the central square of Santiago to mark the one-year anniversary of mass protests that left over 30 dead and thousands injured, with peaceful rallies on Sunday devolving by nightfall into riots and looting, writes Reuters.

People gathered early in the day in demonstrations downtown and in cities throughout Chile that gained size and fervor through the evening. Many touted signs and rainbow colored homemade banners calling for a “yes” vote next Sunday in a referendum over whether to scrap the country’s dictatorship-era Constitution, a key demand of the 2019 protests.

The demonstrations, while largely peaceful early on, were marred by increasing incidents of violence, looting of supermarkets and clashes with police across the capital later in the day. Fire truck sirens, burning barricades on roadways and fireworks on downtown streets added to a sense of chaos in some neighborhoods.

More than 15 metro stations were temporarily closed amid the unrest. Police fired tear gas and water cannons in skirmishes with sometimes violent, hooded and masked people.