The United States on Tuesday urged authorities in Colombia to act with "utmost restraint" to avoid more deaths during anti-government protests that have resulted in at least 19 fatalities.

Protesters in Colombia have called for fresh mass rallies after more than 800 people were wounded in clashes during five days of demonstrations against a proposed tax reform.

"We urge the utmost restraint by public forces to prevent additional loss of life," deputy spokeswoman for the State Department, Jalina Porter, told a press conference.

"The United States is deeply saddened by the loss of life... and sends its condolences to the families and friends of all victims," she added.

US authorities urged restraint after deadly anti-government clashes in Colombia
US authorities urged restraint after deadly anti-government clashes in Colombia AFP / Luis ROBAYO

In the face of the unrest, the government of President Ivan Duque on Sunday ordered the tax reform proposal be withdrawn from Congress, where it was being debated.

Despite the withdrawal of the bill, which protesters said would make Colombia poorer in the midst of the coronavirus pandemic, an umbrella group known as the National Strike Committee called for new demonstrations on Wednesday.

The UN rights office on Tuesday condemned "excessive use of force" by security officers in Colombia during the protests.

The Office of the United Nations High Commissioner for Human Rights voiced "profound shock" at an incident overnight in the city of Cali in which police are alleged to have "opened fire" on demonstrators, reportedly killing and injuring a number of people.