Namibia is facing a “natural disaster” because of poor rains, President Hage Geingob says.

He has declared a state of emergency – the second in three years – over the situation, mobilising all government agencies to respond to the drought.

The lack of rain has already left 500,000 people – one in five Namibians – without access to enough food, the government says.

The sparsely-populated country has seen a succession of droughts since 2013.

The government had set aside $40m (£30m) to buy food and water tanks, and to transport livestock to and from grazing areas.