Protesters clash with police during a national strike against tax reform in Cali, Colombia, Monday, May 3, 2021. Colombia's President Ivan Duque withdrew the government-proposed tax reform on Sunday. (Photo: AP)

The UN rights office condemned Tuesday the "excessive use of force" by security officers in Colombia, after numerous deaths during days of protests against a proposed tax reform.

"We are deeply alarmed at developments in the city of Cali in Colombia overnight, where police opened fire on demonstrators... Firearms can only be used as a measure of last resort," spokeswoman Marta Hurtado told reporters in Geneva.