Juba (AFP) - South Sudan's rebels and army traded blame Wednesday for shooting down a UN helicopter killing three crew and scuppering a day-old ceasefire deal, the fourth in eight months of war.
"The rebels shot it down," army spokesman Philip Aguer said, while rebel spokesman Mabior Garang said: "This was not our work."
The UN Security Council on Wednesday confirmed the cargo helicopter was downed by an "attack" that killed three Russian crew members and injured another, but did not say which side was to blame.
Thousands of people have been killed and more than 1.8 million have fled a civil war sparked by a power struggle between President Salva Kiir and his sacked deputy Riek Machar.
Rebel forces in Unity state, the war-torn region where the helicopter crashed, are led by warlord Peter Gadet, who has been slapped with sanctions for atrocities by both the United States and the European Union.
Aguer said Wednesday the helicopter was "shot by forces of Riek Machar under Peter Gadet".
But rebels insisted the attack took place over an area controlled by the army.
"We were not to blame," Garang told AFP by telephone from Ethiopia.
"Our soldiers on the ground reported that there was an explosion, but according to our reports, it was in the territory held by the government."
The attack has raised deep concern among aid workers and diplomats.
British Ambassador to South Sudan Ian Hughes said the "tragedy underlines the risks humanitarians run daily helping the vulnerable".
UN cargo helicopters are vital to supplying peacekeeping bases and providing food for civilians, particularly as aid agencies have warned of the risk of famine should fighting continue.
Noel Molony, who heads the aid agency Concern Worldwide in South Sudan, said it was "a deeply troubling development in what has already an extremely challenging environment".
Over 45,000 civilians are sheltering in the UN camp in the northern oil town of Bentiu alone, some of the almost 100,000 civilians who have fled to UN bases to escape the conflict.
"We depend on air travel to get both supplies and staff to and from Bentiu, as insecurity and heavy rains make it completely impossible to travel by road to reach people in need," Molony added.
On Monday, warring leaders recommitted to a ceasefire deal after regional mediators threatened sanctions. Like previous deals, it was broken within hours.