Montagnards, ethnic Vietnamese, form the largest group of refugees in Cambodia. Unlike other refugees in the country, known as urban refugees, Montagnards are held in a number of closed sites guarded by police officers in the capital, Phnom Penh. The sites are practically detention centres as residents are only permitted to leave for medical reasons. This policy hinders the provision of education services to this group, and consequently negatively affects their mental health.

The right of states to manage migration flows is subject to their obligations to protect refugees. In fact, the 1951 UN Refugee Convention prohibits states from penalising refugees simply for seeking asylum. Nevertheless arbitrary immigration detention is widely used as a migration control tool. Policies that restrict the movement of refugees carry with them immense human and social costs.