An economic crisis is deepening in Sudan with long queues outside banks and ATMs because of an acute shortage of cash.

When money is available people are being allowed to withdraw only small amounts.

Soaring demand for cash has been caused by inflation and a lack of trust in the banking system.

The currency has plummeted in value - there are now 50 Sudanese pounds to $1, compared with just six in January.

Sudanese economist Abda Almahdi in Khartoum told the BBC's Focus on Africa radio programme that people who have been able to withdraw money have been converting it into US dollars or buying real estate and gold.

Earlier this year there were nationwide protests over the rising cost of living.

Sudan has suffered from a lack of foreign currency since losing three-quarters of its oil reserves when the south of the country seceded in 2011.