A U.N. safety alert to staff members there said the shooting was related to the arrest of the former head of the National Security Service.

Sporadic heavy gunfire has been reported in Juba, the capital of South Sudan, in what appears to be clashes between rival armed groups. A security guard in the Thongpiny area told Radio Tamazuj that the fighting began near the residence of former spy chief Gen. Akol Koor Kuc, before spreading to areas near Juba Airport.

South Sudan's President Salva Kiir held an urgent meeting of top security brass on Friday after a shootout at the home of powerful former spy chief Akol Koor, who was sacked almost two months ago amid rumours of a coup plot.

South Sudan security forces were investigating Friday a shootout at the home of the troubled nation's powerful former spy chief Akol Koor, who was sacked almost two months ago amid rumours of a coup plot.