S.Sudan Rebels Face Sanctions after Killing Ceasefire Monitor

Warring sides in South Sudan face "punitive sanctions," the rebels for killing a ceasefire monitor and the government for violating a truce, the top mediator of the stalled peace talks has warned.

"The violators of the cessation of hostilities agreement, and those responsible for the death, will bear the consequences," chief mediator Seyoum Mesfin said in a statement late Sunday, from the regional east African IGAD bloc.

"We cannot continue to treat this matter with velvet gloves," he added.

Rebel forces arrested the IGAD monitor on Saturday after the team landed near the town of Bentiu, in war-torn northern Unity state, the bloc said.

"The monitors, who are part of the eight verification teams, had landed in the Unity State town for their routine inspection mission before being arrested and marched to an unknown destination," the IGAD statement read.

Rebel forces in Unity are led by rebel commander and warlord Peter Gadet, who has been sanctioned by both the United States and European Union for atrocities.

IGAD did not clarify how the monitor was killed, but security sources said man was beaten to death.

There was no immediate response from the rebels.

Regional leaders were expected to meet late Monday in Ethiopia to discuss the more than eight-month long civil war, where they are due to "spell out the punitive measures" for South Sudan, IGAD said in a statement.

IGAD leaders have repeatedly threatened measures if both sides continue to violate previous peace deals.

Thousands of people have been killed and more than 1.5 million have fled civil war sparked by a power struggle between President Salva Kiir and his sacked deputy Riek Machar.

The United Nations has said the food crisis is the "worst in the world", with aid workers warning of famine if the conflict continues.