Sudan's paramilitary Rapid Support Forces and allies have signed a charter that paved the way for the establishment of a parallel government, as Sudan's army made advances recently against the rival groups.

Sudan's Rapid Support Forces signed a charter with allied political and armed groups late on Saturday to establish a "government of peace and unity", signatories al-Hadi Idris and Ibrahim al-Mirghani told Reuters.

Sudan's paramilitary Rapid Support Forces and its allies have agreed to form a parallel government, they said Sunday, despite warnings such a move could further fragment the war-ravaged country.