Colombian authorities are investigating 10 police officers who allowed civilians to shoot at demonstrators in Cali, a high-ranking official said on Monday, while the attorney general"s office linked three more deaths to protests. The Andean country has seen more than a month of protests against the social and economic policies of the government of President Ivan Duque. The demonstrations were sparked by a now-withdrawn proposed tax reform. Since the tax reform was withdrawn, protesters" demands have expanded to include a basic income, opportunities for young people and an end to police violence, including the dissolution of the feared anti-riot unit ESMAD. Protests have been marked by violence. The attorney general"s office on Monday said 20 deaths have been linked to demonstrations - three more than a previous tally - while rights groups report dozens more protesters have been killed by security forces. Colombia"s third-largest city Cali, which has become an epicenter for protests, once more saw bloodshed on Friday with civilians and even an off-duty agent of the attorney general"s office shooting at demonstrators, the attorney general said. read more An investigation has been launched to identify those who broke the law in Cali, General Jorge Luis Vargas, director of Colombia"s national police, said on Monday, adding that information concerning officers who may have broken the law or not performed their duties has been sent to the military justice unit. Over the weekend Cali Mayor Jorge Ivan Ospina reported more than a dozen violent deaths took place in the city on Friday and reported armed men shooting at demonstrators in the presence of the police. read more The United Nations High Commissioner for Human Rights, Michelle Bachelet, on Sunday called for those responsible for the violence in Cali to be held accountable. "It is essential that all those who are reportedly involved in causing injury or death, including state officials, are subject to prompt, effective, independent, impartial and transparent investigations and that those responsible are held accountable," she said. As the death toll rises, negotiations between the government and protest leaders have stalled. The government says protesters must condemn and reject road blocks before further negotiations take place. Protest leaders accuse the government of backtracking on earlier commitments. The national strike committee has called for more protests to take place on Wednesday.