Waikeria Prison remains in lockdown today as an 18-hour stand-off between prisoners and guards continues, with rioting inmates setting fire to mattresses on the rooftop overnight.

Sixteen Waikeria prisoners are still refusing to surrender this morning. Four had given up overnight, but the jail has been significantly damaged.

The 16 prisoners remained within the secure perimeter of the top jail facility.

Damage to the top jail appeared to be significant. While the condition of the building will need to be assessed, it was unlikely that prisoners will be accommodated there again, Corrections said in a statement.

It said there has been no loss of life or injury to staff or prisoners. Fire and Emergency NZ, Police and St John remain at the prison and are working closely with Corrections staff.

Corrections described the prisoners behind the revolt as "non-compliant".

Late yesterday, 49 prisoners were evacuated from the rioting sector facility to another unit in the prison. Overnight a further 163 men were temporarily moved to other locations within the prison, said the spokesperson.

Specialist Advanced Control and Restraint teams, made up of staff from a range of prisons, are at the jail, where inmates have been rioting since early Tuesday afternoon.

Photographs emailed to NZME late last night showed a large cloud of smoke visible from neighbouring farmland.

Police, firefighters and St John confirmed they were still onsite as Corrections officers continued to try to negotiate with the inmates and ensure the safety of everyone at the prison.

A spokesperson said yesterday that 19 prisoners had been seen on the roof of the building. This included those who were involved in lighting fires in a yard earlier today, along with several others who were able to get out of their cells.

"The prisoners have been able to access some parts of the building by breaching the roof space, however their movement inside the building is restricted by internal gates, barriers and secured doors.

"There is a large amount of smoke around the building, which is coming from mattresses set alight by the prisoners."

"There are around 230 prisoners in total in the 'top jail' facility and we will not hesitate to evacuate further prisoners if it becomes necessary in order to keep them safe."

FENZ was originally called to Waikeria after inmates lit several fires in the prison's exercise yard on Tuesday afternoon.

About 20 prisoners were using the yard at the time.

The situation was thought to be under control before nine prisoners refused to comply with instructions, Newshub reported.

Offenders allegedly took toilet doors off their hinges and used them as weapons against staff.

Corrections Association president Alan Whitley said the union was offering support.

"We're always concerned about people when a situation like this is going on, but we've got specialised teams that have got specialised training, they're professional people and they'll do a professional job to get the situation under control," Whitley told RNZ.

St John treated a number of staff and prisoners due to smoke inhalation. Earlier in the evening it was thought at least one prisoner was bleeding after an altercation with guards.

A prisoner on remand said a riot at the prison had been imminent, with prisoners protesting for basic human rights. They claimed there were issues at the prison, including toilet paper taking days to be provided, Newshub reported.

Last year, two Waikeria Prison Correction officers were punched in the face within nearly as many days, while fighting between prisoners has also been reported.

A prisoner punched an officer in the face and another officer was also injured when he stepped in to help.

That altercation came after an officer was threatened and punched a few days earlier.

There had also been reports beforehand of prisoners fighting among themselves.

Waikeria Prison is one of New Zealand's biggest prisons, located on a 1200ha site south of Te Awamutu in the Waikato region.

The "top jail" where the inmates are currently contained was built in 1911 and is the oldest part of the prison. It is being replaced by a new facility being built at the prison and which is scheduled to open in 2022.