Angola's President Joao Lourenco says illegal immigration linked to diamond mining has reached alarming levels.

In a speech to parliament he said the government was going to reform the mining sector and commercialise the diamond industry.

Since the beginning of the month tens of thousands of people have been deported - most to the Democratic Republic of Congo.

Some of those forced to leave say Angolan police and soldiers shot dozens of people dead and looted homes during the operation to clear out immigrants.

The Angolan police denied the reports.