Migrants stranded in Spain's North African enclave of Ceuta are building makeshift camps along the beach as overcrowded reception centres struggle to cope with the latest migration crisis.

Hundreds of Nigerians returned to Lagos from South Africa on Tuesday on a government-backed evacuation flight, as anti-immigration protests demanding that foreign workers leave continue in parts of the country.

The International Organization for Migration (IOM) says it is worried about anti-immigration protests in parts of South Africa, citing safety concerns and potential human rights violations.

The Fellowship of Christian Councils in Southern Africa (FOCCISA) has condemned the rise in xenophobic attacks, hate crimes and speech targeting migrants in South Africa.

Malawian nationals gathered outside Malawi's Consulate General in Johannesburg on Thursday, saying they feared for their safety as a June 30 ultimatum from anti-migrant groups drew closer.