In the capital, Lima, demonstrators threw glass bottles and stones, as fires burned in the streets, defying police teargas.
In the southern Puno region about 1,500 protesters attacked a police station in the town of Ilaveo. A police station in Zepita, Puno, was also on fire.
Eight patients hospitalised with injuries in Ilaveo, including broken arms and legs, eye contusions and punctured abdomens.
By late afternoon, 58 people had been injured nationwide in demonstrations, according to a report from Peru’s ombudsman.
The unrest followed a day of turmoil on Thursday, when one of Lima’s mansions burned to the ground.
Thousands of protesters descended on Lima this week calling for change and angered by the protests’ mounting death toll, which officially stood at 45 on Friday.
At the beginning of the Friday’s protests, the demonstrators seemed more organised than the previous day and they took over key roads in downtown Lima.
Police appeared more combative than the day before and after standing watch over protesters that had been blocked into downtown streets, they started firing volleys of teargas.
In the Cusco region, Glencore’s major Antapaccay copper mine suspended operations on Friday after protesters attacked the premises – one of the largest in the country – for the third time this month.