BOGOTA, Colombia (AP) — The United Nations human rights office said it was “deeply alarmed” over violence against protesters in the Colombian city of Cali, where “police opened fire on demonstrators” and allegedly killed and injured several people Monday night.

The statement from the U.N. High Commissioner for Human Rights comes as antigovernment protests sparked by proposed tax increase enter their sixth day and show few signs of stopping.

According to Colombia’s Human Rights Ombudsman, 16 protesters and one policeman have been killed in the demonstrations since last Wednesday. But that figure doesn’t include reports of deaths in Cali on Monday, which the U.N. said it is still trying to confirm.

The protests began after Colombia’s government proposed a tax plan aimed at raising $6.7 billion to pay the country’s debts and maintain a basic income scheme for 3 million low-income people that started during the pandemic.

President Iván Duque withdrew the tax plan on Sunday amid the protests and his finance minister resigned the following day, but large demonstrations and roadblocks have continued.

Numerous videos have emerged on social media showing police using excessive force during the protests and even shooting at some demonstrators point blank.

In its statement, the UN urged Colombia’s government to protect the rights of protesters.

“Law enforcement officers should abide by the principles of legality, precaution and necessity of proportionality,” the statement said.

Later on Tuesday a group of eight non-government organizations including Oxfam and the Washington Office on Latin America published a statement asking Duque to stop using the military to control protests. The Biden administration also made a statement urging Colombian police and protesters to practice restraint.

“All over the world citizens in democratic countries have the unquestionable right to protest peacefully,” the statement read. “We urge the utmost restraint by public forces to prevent additional loss of life.”

Duque said in a statement issued Tuesday that his government would act with “resolve” against groups using the protests to provoke violence. The resident announced that his government would create “spaces” for civil society groups, political parties and the private sector to meet with government representatives.