This briefing paper focuses on fighting during 2011 in Mayom County - in the western part of Unity State - between the SPLA and armed opposition forces originally loyal to Peter Gadet and other Nuer commanders. The briefing documents serious human rights abuses and violations of international humanitarian law, as well as the origins and where possible supply routes of key weapons and munitions used by the different parties to commit such abuses and violations: weapons and munitions which in many cases have been either newly manufactured or newly delivered to both sides.