The UN refugee agency has warned that Angola's deportation of more than 300,000 nationals from the Democratic Republic of Congo this month has left them in an extremely precarious situation.

The UNHCR said there were many allegations that migrants had been killed, reportedly by the Angolan security forces, with six deaths confirmed.

It urged the Congolese government to help the returnees, saying that many had insufficient access to food, water, healthcare and proper sanitation.

The mass expulsions coincide with the Angolan government's plan to reform its diamond industry; large numbers of Congolese had worked in informal mining operations.