BOGOTA, Dec 13 (Reuters) - Colombia"s national police are responsible for the deaths of 11 people during anti-police brutality protests last year, a report sponsored by the United Nations said on Monday. A series of demonstrations against President Ivan Duque"s unpopular government have led to more than 40 civilian deaths since 2019, according to government figures. Victims" families and human rights groups say many of the deaths are driven by heavy-handed policing and they have criticized slow-moving prosecutions of those allegedly responsible. The September 2020 death of taxi driver Javier Ordonez, shown in a viral video writhing on the ground while being repeatedly tasered by police as he screamed for them to stop, sparked several days of demonstrations in Bogota. "The events of violence, abuse and police brutality which began in the early hours of Sept. 9 with the murder of Javier Ordonez at the hands of members of the national police set off one of the most serious episodes of violation of human rights in the history of Bogota," said the report, headed by the country"s former ombudsman Carlos Negret and funded by the United Nations. Of 14 people killed in connection with protests, 11 died as a result of actions by police, who openly disregarded standards for use of force, it said. "There was a massacre, the responsibility for which falls on the national police," the report said. Asked about the report, a police spokesperson directed Reuters to comments made earlier this year by police head General Jorge Luis Vargas, who has repeatedly asked forgiveness for the 2020 deaths and said more than a dozen officers have been subject to disciplinary action. So far, one officer has been convicted for Ordonez"s death. There report also documented arbitrary detentions, gender-based violence, and violence against police during the demonstrations. The investigative strategy being used by the attorney general"s office risks continuing impunity for those guilty of the killings, the report said. A spokesperson for the attorney general"s office said it had not yet been able to study the report in detail.