The United Nations rights chief on Thursday accused Czech authorities of systematically detaining migrants and refugees in "degrading" conditions, as part of a policy to dissuade them from entering the country.

"According to credible reports from various sources, the violations of the human rights of migrants are neither isolated nor coincidental, but systematic: they appear to be an integral part of a policy by the Czech Government designed to deter migrants and refugees from entering the country or staying there," UN High Commissioner for Human Rights Zeid Ra'ad Al Hussein said in a statement.