At least three inmates died following a Peruvian prison riot over the demand for better sanitary measures and coronavirus medical care, the country's prison authority said.

The protest by inmates, who were also calling for pardons, began Monday afternoon at the Miguel Castro Castro prison, located in the San Juan de Lurigancho district, according to Gerson Villar, head of the National Penitentiary Institute (INPE). The riot was controlled later in the day.

“The cause of their deaths is being investigated,” Villar said of the three inmates who died, speaking to local channel America Television.