South Sudan's president has accused government officials of plundering at least $4bn (£2.6bn) from state coffers.

In an extraordinary letter to more than 75 current and former senior government staff, Salva Kiir demands that they return the stolen funds.

Corruption has plagued the government of South Sudan, one of the world's poorest countries, since the 2005 peace deal that ended more than 20 years of civil war with Sudan, paving the way for independence last July.

"We fought for freedom, justice and equality," the president'sKiir's letter reads. "Yet, once we got to power, we forgot what we fought for and began to enrich ourselves at the expense of our people."