To mark 20 years of mandatory detention for asylum seekers in Australia, an international campaign has been launched to end the imprisonment of children.

Australia is the only first world country with a policy of mandatory indefinite detention for asylum seekers who arrive by boat. Up to 4,000 people are held under this policy.

Campaigners say locking children up in prison is unnecessary, unethical and harmful.

Al Jazeera's Andrew Thomas reports from Melbourne.

Source: Al Jazeera