A growing number of refugees from war-torn countries are committing violent acts and threatening the safety of Queensland communities, according to a District Court judge.

Leanne Clare said the Brisbane District Court is seeing a 'significant' amount of violent refugees, as she sentenced Hamad Ardadi Tuba for threatening to kill two students with a fake gun, before robbing one of them.

The former Yeronga State High School student, then 17, pleaded guilty to the 'chilling' act in June 2016 - five years after he arrived in Australia from North Africa.

Judge Clare handed him a suspended two-year sentence for armed robbery and two-and-a-half years' probation for threatening violence, The Courier Mail reported.

Judge Leanne Clare said the Brisbane District Court (pictured) is seeing a 'significant' amount of violent refugees, as she sentenced Hamad Ardadi Tuba for threatening to kill two students with a fake gun, before robbing one of them

Judge Clare said a growing number of refugees from war-torn countries are committing violent acts and threatening the safety of communities (pictured is African youth crime in Victoria)

'This court is seeing a lot of, a significant number of, refugees ... and they resort to violence and that has to be a concern for the protection of the community,' Judge Clare said.

Speaking of Ardadi Tuba's actions, she said: 'The offences display a chilling capacity to instil fear and a willingness to frighten others into submission for some perceived minor offence.

'I have been in criminal law for over 30 years and the emergence of this kind of offending by juveniles is an alarming new development.'

Ardadi Tuba held a silver replica gun to a boy's head at the Westfield Garden City shopping centre, in Brisbane's south, before asking him 'Do you know who I am?' and stealing his money and mobile phone.

Earlier he held the gun under his shirt, pretending it was a real one to threaten another student at Sunnybank State High School.

Ardadi Tuba threatened the two students as an act of revenge because he thought they were bad-mouthing him, court heard.

'This court is seeing a lot of, a significant number of, refugees ... and they resort to violence and that has to be a concern for the protection of the community,' Judge Clare said (pictured is an African teen being arrested in Tarneit)

Speaking of Ardadi Tuba's actions, Judge Clare (pictured) said: 'The offences display a chilling capacity to instil fear and a willingness to frighten others into submission for some perceived minor offence'

Ardadi Tuba held a silver replica gun to a boy's head at the Westfield Garden City shopping centre (pictured), in Brisbane's south, before asking him 'Do you know who I am?' and stealing his money and mobile phone

He was born in Eritrea and grew up in an Ethiopian refugee camp where his father died, the publication reported.

Judge Clare said Ardadi Tuba experienced a traumatic childhood which partially explained his behaviour.

But she told him he now lives in a 'peaceful country' that will not tolerate his violent actions.

Ardadi Tuba moved to Australia when he was 12 and now lives with his mother and disabled brother.

He faces deportation to Eritrea if he re-offends while on probation, Judge Clare warned.

He already spent nearly four months behind bars while on remand between June and September 2016.