Protesters took over the Engineering University in Managua, the capital, demanding greater democracy and Mr Ortega’s resignation.
Pro-government radio station Radio Ya, whose offices are located near the university, were partially set on fire during the demonstration.
Protests also broke out in the city of Masaya where the prosecutors’ offices were set on fire.
Police were sent to contain the protests and there were reports of injuries.
Protests erupted on 18 April after Mr Ortega imposed austerity measures for Nicaragua’s social security system that raised income and payroll taxes while reducing pension benefits by 5%.
At least 76 people died amid a violent response from police and government-allied Sandinista youth groups, with demonstrations involving mostly elderly individuals, university students and other activists.
Authorities were seen using live ammunition on protestors while also arming pro-Sandinista groups with weapons.
After five days of unrest in cities across Nicaragua, Mr Ortega announced the cancellation of the reforms – but the protests have erupted again.
The International Federation of Human Rights (FIDH) has expressed concern about serious human rights violations by the government in suppressing the protests.
Four people were killed during clashes on Saturday as thousands participated in protests by barricading roads and shouting anti-Ortega chants.