A teenager involved in a riot in which a fellow inmate’s cell was set alight and guards were assaulted at Darwin’s Don Dale youth detention centre has been handed a four-year jail term.

The youth, who cannot be named, was 16 when he took part in a three-hour rampage through the notorious facility on 6 July last year.

At one stage he yelled out “die motherfucker die” to the fellow youth whose cell was torched but who was unharmed.

In November last year there was another riot at Don Dale allegedly involving some of the same youths, which received widespread publicity.

However the July incident only became publicly known in December, prompting accusations of a Northern Territory government cover-up.

Fire damage at Don Dale Detention after November’s riot. Photograph: STRINGER/Reuters

The group of four had just eaten dinner when they refused a request to shower and prepare for lockdown.

They reacted by violently threatening two youth justice officers who retreated to the front office area.

The youths then “ran amok”, NT supreme court Justice Peter Barr said during sentencing on Wednesday, arming themselves with metal table legs and breaking into numerous areas including another block where inmates were sleeping, and damaging property.

They pursued the youth justice officers and struck a metal roller door and window before spraying them with a dry fire extinguisher.

Both officers found it hard to breathe and one started vomiting, Barr said.

They stole vehicle keys, scissors, screwdrivers, paint thinner, batons and a riot shield, he said. They started a grass fire and set fire to two other blocks but the fires did not spread.

They then reached a centre radio and spoke to police, asking for cigarettes and fast food and a key to the K block, where a youth they’d recently fought with was sleeping.

“As subsequent events show, you still had ill feelings or bad blood towards him,” Barr said.

When they could not get into the block, they approached the youth’s cell window outside, telling him “We are going to slash your throat”.

The paint thinner was used to set the window and wall alight, causing wiring and air conditioner damage.

“You are gonna die in there,” they said to the detainee, who “could see flames at the window but was unable to leave his cell”, Barr said.

“It is quite unclear what you would you have done if you had been provided with means to access K block … that is therefore deeply concerning,” he said.

The youth pleaded guilty to arson, property damage, making a threat to kill and assaulting the two workers.

He had been abandoned at birth and suffered from foetal alcohol spectrum disorder, which affects cognitive function, and conductive hearing loss.

Now 17, he has been in and out of detention since he was 10.

He will be eligible for parole after serving 18 months.