Hundreds of police and soldiers were deployed to take control of Tuminting prison in Manado city, the capital of North Sulawesi province, which is designed to house 490 inmates but now has more than 550, said Lukmasono, the head of Justice and Human Rights provincial office.
Lukmasono, who goes by a single name, a preliminary investigation revealed that many inmates, mostly drug offenders, were angered by restrictions on family visits and envious following the early release of 115 inmates to curb the spread of the coronavirus in prisons.
They went on the rampage and started fires, and other inmates joined the protest and it turned violent, but there were no reports of deaths, Lukmasono said.
Television video showed prisoners in an open field under heavy guard by soldiers while orange flames and black smoke billow from a building, and burned office equipment, documents and broken glass are scattered around the prison.
Indonesia has released more than 36,550 inmates in a desperate bid to stop coronavirus from rampaging through its notoriously overcrowded prison system, said Rika Aprianti, the directorate general of Corrections at Justice and Human Rights spokesperson.
Inmates due to have served two-thirds of their sentences by December will be freed under assimilation and reintegration programs, the ministry said in a decree. It said juvenile inmates set to have served half their jail terms by December will also be released.
Indonesia recorded 3,842 confirmed COVID-19 cases as of Saturday, with 327 deaths.
Jailbreaks and riots are common in Indonesia, where overcrowding has become a problem in prisons that are struggling with poor funding and large numbers of people arrested in a war on illegal drugs.
Associated Press writer Niniek Karmini in Jakarta, Indonesia, contributed to this story.