Zimbabweans are the aliens:

South Africa is to start expelling Zimbabweans again, from 31 December, the government has announced, ending their special status.

The deportations were halted in April 2009 following an influx of those fleeing political instability and economic meltdown in Zimbabwe.

An estimated two million Zimbabweans are thought to be in South Africa.

Their presence is one reason cited for outbreaks of xenophobic attacks in recent years.