A total of 90 people already died in the protests, which started this April and where started against the plans of the government to cut in social welfare. The cuts where later on rejected but the protests did not stopped and evolved in a general protest against President Daniel Ortega.
Officials say they only shot at delinquente groups who where protesting with violence.
Police officer Francisco Diaz said:
"The number of people killed as a product of the actions of delinquent groups who operate wearing masks is 15".
Government officials are officially investigating the deaths.
President Daniel Ortega runs a socialist government and is in office since 2007.