NAIROBI (Reuters) - Four of the six aid workers killed in an ambush in South Sudan over the weekend were Kenyans working for a local non-governmental organisation, Kenya's government said on Tuesday.
An official with the United Nations said the attack on Saturday, the deadliest single assault on humanitarian staff in a three-year-old civil war, could amount to a war crime. [L5N1H30TS]
No side has taken responsibility for the attack on the six, who were ambushed as they travelled from the capital Juba towards the town of Pibor through remote territory largely under government control but fought over by both sides and plagued by militia and other armed groups.
"The six were ambushed and murdered by unknown gunmen," the Kenyan foreign affairs ministry said in a statement.
The U.N. in Juba had told Reuters the dead aid workers were Kenyan and South Sudanese without giving a breakdown of the nationalities.
The six were working for a local NGO called GREDO, the ministry said, and had been funded by UNICEF to build youth centres in Pibor.
The Kenyan government said it was working with both organisations and South Sudanese security personnel to retrieve the bodies.
At least 79 aid workers have been killed since President Salva Kiir's government forces clashed with his former deputy Riek Machar's men in December 2013. A long-running rivalry between the two has split the country along ethnic lines.
U.N. monitors have found Kiir's government mainly to blame for the catastrophe in a country which, in less than six years of independence, has collapsed into a chaotic ethnic war and an epidemic of rape and famine.
Reporting by Duncan Miriri, editing by Ed Osmond