Local media showed images of inmates climbing to the roofs of the prisons, calling for medicine and access to doctors.
"We urge the entry of medical teams to do an evaluation inside the prison facilities to prevent more deaths," said Cochabamba ombudsman Nelson Cox.
Eight inmates in total have died with symptoms of COVID-19, according to Cox, spiking concerns that the virus will spread throughout the prison population.
"There are no doctors, there are no medicines. They are dying inside," said Susana, a relative of a prisoner in the San Sebastián prison who declined to give her last name. "It is not possible to let them die. We are human beings."
Authorities have reported more than 60 deaths due to the coronavirus in Bolivia's prison system, which is overcrowded at more than 240% capacity. There have been several other deaths in recent months that were not confirmed as caused by the coronavirus due to a lack of testing.