The Northern Territory’s notorious Don Dale youth detention centre is in indefinite lockdown after a group of inmates set fire to the education centre and climbed the roof as part of a riot.

Police were called to the centre on Wednesday afternoon after reports of smoke billowing from the education facility and 14 children on the roof of the building.

The children allegedly threw projectiles at staff and police, sending an officer to hospital with a fractured leg.

On Thursday morning six children remained on the roof but were removed by 9am.

Territory Families chief executive Emma White said the facility was now in indefinite lockdown as an investigation occurred.

“The nature of the young people in Don Dale is adolescents that have very complex backgrounds … they have often really problematic behaviours,” she said on Thursday.

“And sometimes that involves conflict and that’s what happened yesterday and has escalated.”

White said the department was hoping the investigation would be complete on Thursday afternoon and children could be released from lockdown.

NT Minister for Territory Families Ngaree Ah Kit said the centre was fully staffed at the time and police were called to de-escalate the situation.

“I wish I could give a guarantee that all the staff we have in place … will stop a young person from causing a serious incident like yesterday, “she said.

“The answer is no I can’t.”

The NT’s Territory Response Group (TRG), which is under ICAC investigation for a series of racist “awards” uncovered during a coronial inquest, was sent in to manage the riot.

Acting Police Commissioner Martin Dole said he was not concerned about using the response group.

“TRG is a professional outfit and we continue to use them across the territory in deployments,” he told reporters on Thursday.

Latest NT corrections data shows more than 90 per cent of Darwin’s youth detainees are Indigenous and almost half are under the age of 14.

Dole said the children who participated in the riot would be charged.

“Suffice to say criminal damage will be among (the charges), assault police and probably engage in a riot I would assume,” he said.

NT Chief Minister Eva Lawler labelled the children “some of the worst-behaved children in the NT”.

“There are a number of young people who have displayed abhorrent behaviour,” she said.

“There will be actions that flow from that.”

Graphic footage was shown on ABC TV in 2016 of four detainees being tear-gassed at the facility.

That led to the 2017 Royal Commission into the Protection and Detention of Children.

The NT government accepted in full or in principle all 227 recommendations at an estimated cost of $229 million, including the closure of Don Dale.

Five years after the recommendation, the facility remains open and critics say the government is dragging its feet.

With an election due in August, Lawler said she remains committed to closing the facility.

A replacement facility was due to open in 2023 but the government has continued to blame building approvals, staffing and COVID-19 for delays.

“It will be an outstanding facility when it’s completed and truly it can’t be open soon enough,” Lawler said.

The latest disturbance comes four days after reports of a similar incident, involving detainees climbing onto the roof.

– AAP