Peace talks between South Sudan's warring parties resumed Monday in Addis Ababa after a three-week interruption, said East African bloc IGAD that is mediating in the 4.5-month-oldconflict, dpa reported. IGAD, or the Intergovernmental Authority on Development, said it held consultations with President Salva Kiir, rebel leader Riek Machar as well as the African Union and the United Nations. The government and rebels "shared concern over the recent escalation of the conflict and expressed their renewed commitment to the mediation process," a statement said. A recent government decision to release four high-ranking Macharsupporters from prison has raised hopes of an agreement. A ceasefire signed in January has not stopped the fighting, which has intensified again in recent weeks. A power struggle between Kiir and Machar turned violent mid-December when fighting erupted between soldiers belonging to their respective ethnic groups, the Dinkas and the Nuers.