Calls for leadership grow amid rising anti-immigrant mobilisation.

At a time of rising tension across parts of South Africa, Amnesty International South Africa has warned that stronger political leadership is urgently needed to confront xenophobia, its underlying causes and the growing climate of intimidation directed at foreign nationals.

The organisation raised concern over the continued mobilisation of a private anti-migrant group which has issued an "unlawful" June 30 deadline for undocumented migrants to leave the country, alongside planned marches in several provinces.

Amnesty warned that South Africa risks repeating some of its darkest chapters if decisive action is not taken.

"Amnesty International supports the right to peaceful protest. But violence, intimidation, harassment and self-appointed 'enforcement' of immigration laws is unlawful and has no place in our society. History has shown us where this path leads and how quickly things can turn deadly," said executive director Shenilla Mohamed.