UN Secretary General Ban Ki Moon has called on President Salva Kiir and Dr Riek Machar to immediately cease military operations.

In a statement, Mr. Ban says the ongoing fighting in Upper Nile and Unity states undermines the efforts of IGAD to find a political solution to the conflict.

“This fighting is unacceptable. It is part of a series of violations of the Cessation of Hostilities Agreement signed by the parties on 23 January 2014 and undermines the ongoing IGAD efforts to find a political solution to the conflict in South Sudan,” read the statement.

Mr Ban condemned the escalation of hostilities and urges all parties to the conflict to protect civilians under international human rights and humanitarian law.

“They must respect the inviolability of UNMISS premises, including protection of civilian sites, which are now host to more than 120,000 IDPs.”

The statement comes after two mortar bombs landed in the UNMISS compound in Maluth, killing four people and wounding eight others on Tuesday.