Colombia has become the latest country in Latin America to be hit by anti-government protests.
Around 200,000 people hit the streets on Thursday, authorities said.
They are upset with the government of President Ivan Duque, including rumoured economic reforms and ongoing anger at what protesters say is a lack of action to stop corruption and the murder of human rights activists.
It comes amid demonstrations elsewhere in Latin American countries in recent months, including anti-austerity marches in Chile, protests over vote-tampering allegations in Bolivia that led President Evo Morales to resign and inflamed tensions in crisis-hit Nicaragua.
The marches in Colombia began peacefully but violence erupted in the evening. Three people died during the protests, the country's defence minister announced on Friday.
Footage and images posted on social media purported to show people looting shops and banks with clashes breaking out between looters, police and armed civilians organised in groups to defend their neighbourhoods.
The violence led Maurice Armitage, the mayor of Cali, a city in the southern Valle del Cauca province, to impose a curfew from 19:00 local time on Thursday, warning that "those outside after that time may be detained by the authorities".
But on Friday, Defense Minister Carlos Holmes Trujillo told journalists that three people had died in the province.
"In the last few hours authorities have confirmed the death of two people in Buenaventura in the midst of disturbances and one more in Candelaria, both municipalities of Valle," he said, adding that a group of people intended to loot the Viva Buenaventura mall.
"Because of this violent act, the security forces went to confront the event, while being subject to violent aggression with the throwing of rocks and sticks. As a result of the confrontation between vandals and security forces and in events that are the subject of an investigation by the attorney general's office, two people were killed," he also said.
Further protests were expected on Friday after former leftist presidential candidate Gustavo Petro urged people to bang pots and pans in Bogota's central square in a traditional expression of protest known as a "cacerolazo". Unions, however, did not support his call.