Tags: Salva Kiir

South Sudan's warring sides have violated a ceasefire agreement over 50 times in the last 20 months, mediators said in a report on Thursday.

South Sudanese rebels and the army have accused each other for the second time this week of attacks, this time barely a day after President Salva Kiir signed a peace deal that looks increasingly fragile.

South Sudan's president signed a peace deal on Wednesday to end a 20-month conflict with rebels, but he told regional African leaders at the ceremony that he still had "serious reservations".