“Relevant international standards require that detention be used only as an exceptional measure, justified, narrowly tailored and proportional in each individual case, and that it be subject to judicial review,” the experts said.

The law could result in potential discrimination against Mexicans, indigenous peoples and other minorities in Arizona, the U.N. officials said.

They also said they are concerned about the enactment of a law prohibiting Arizona school programs featuring the histories and cultures of ethnic minorities because everyone has the right to learn about his own cultural and linguistic heritage.