The United Nations has declared a famine in parts of South Sudan, the first to be announced anywhere in the world in six years.

Reports say about 4.9 million people or about 40 percent of that country’s population is in need of urgent food aid.

UN agencies says 100 000 people are facing starvation in South Sudan and a further one million are classified as being on the brink of famine.

UN’s Food and Agriculture Organisation representative in South Sudan, Serge Tissot said the basic cause of the famine is conflict, citing Yemen, Nigeria and Somalia as other countries affected by famine.

He said the country has been at war since 2013 and more than three million people have been forced to flee their homes.

Mr Tissot said crop production has been severely curtailed by the conflict with livestock dying.

In Yemen, a multi-party civil conflict has drawn in regional powers, causing widespread destruction, economic damage and loss of life while Nigeria and Somalia have faced insurgencies by extremist islamist groups Boko Haram and Al-Shabab, respectively, leading to large-scale displacement of people, disruption of agriculture and the collapse of normal trading and market activities.