Corrections officers have been negotiating with at least nine prisoners at a Waikato prison where inmates earlier set fires as part of a riot.
The inmates at Waikeria Prison, near Te Awamutu, refused to comply with staff and damaged prison property.
"The prison remains locked down. The incident is contained, and there is no threat to the safety of the public," a spokesperson for Corrections said.
Emergency services were called to the prison on Tuesday afternoon after prisoners lit several small fires in the exercise yard they were in.
The fires were extinguished but crews remained on site for some time.
"There were around 20 prisoners in the yard when the fires were lit, however a number are not taking part in the incident. We have comprehensive procedures for managing events of prisoner disorder," the Corrections spokesperson said.
Newshub understands some prisoners suffered smoke inhalation.
An inmate at the prison contacted Newshub saying 20-30 prisoners were involved in the riot and that they were protesting conditions and treatment at the jail.
"We just want basic human rights," the inmate said.
"Treat us like animals and we'll act like animals."
Both Corrections and the inmate said they want the situation to be resolved safely.