South Africa faces a critical juncture as anti-immigration sentiments rise, threatening not only the lives of African migrants but also the country's economic stability and regional relationships.

Police were braced for unrest as the clocked ticked down on a deadline set by anti-migrant groups for illegal immigrants to be deported, or leave.

Businesses in South African cities have been shuttered and police have been deployed to the streets across the country because of fears that anti-immigration protests could turn…