Violent protests fueled by outrage at a now-canceled tax plan began on April 28. Demonstrator demands have expanded to include a basic income, an end to police violence and the withdrawal of a long-debated health reform.
Smaller protests and road blockades have continued daily around the country. Unions and student groups have called for a national strike on Wednesday after a meeting with President Ivan Duque left them at odds with the government.
Colombia's human rights ombudsman said it had received reports of the deaths of 41 civilians and one police officer. It is verifying if they are directly connected to the protests.
The police and its ESMAD riot squad are presumed responsible for 11 killings, the ombudsman has previously said, while it classed seven deaths as unrelated to the marches themselves.
"We call for all necessary measures to be taken to put an end to the violence that is bleeding Colombia dry," the ombudsman's office said on Twitter.
Local advocacy group Temblores says 40 protesters have allegedly been killed by police, while Human Rights Watch said it has received 46 credible reports of protest deaths and verified 13.
So far three police officers are facing murder charges connected to demonstrator deaths.
Duque visited the city of Cali - a focal point for protests - for a second day in a row on Tuesday and announced poor and working class students at public universities and technical schools will pay no tuition next semester.
The center-right president lacks strong backing in Congress, where his tax proposal, which would have expanded items subject to sales tax, was heavily criticized. His term ends in August next year.
The three largest cities in Colombia, which has recorded nearly 79,000 COVID-19 deaths, are now bracing for an extended third peak in coronavirus cases and over-stretched intensive care units, local authorities said.
Capital Bogota is confronting a "hospital collapse," Mayor Claudia Lopez said in a press conference on Monday, and will not see infections drop this week as previously predicted.
A fall in infections will not come until the end of May, Lopez said, adding that protests make quarantine restrictions nearly unenforceable, although she extended a curfew and restriction on alcohol sales.
Medellin, whose ICUs have been at or near full-capacity for weeks, is preparing for a possible crisis, health secretary Andree Uribe told Reuters in a video.
"We know there will be an increase in cases, we're on alert, we are carrying out actions for early identification, like testing everyone who participated in the marches," she said.
In Cali, demonstrations are likely to extend a current peak, health secretary Miyerlandi Torres said.
"We're worried about marchers who don't comply with any of the self-protection protocols like physical distancing and the use of face masks," she said. "And with the presence of strains like the British one, which are highly contagious, it's indicated the figures won't fall in the short term."
Cali's ICUs are about 95% occupied, according to local government figures.
