South Sudan river ambush kills at least 40-official

* Tribal fighters ambush U.N. food barges
* Fears grow for thousands of hungry people
* Violence threatens fragile peace after 2005 accord
* Concern over possible retaliation
(Adds U.N. source on fears of retaliation)
By Andrew Heavens
KHARTOUM, June 14 (Reuters) – At least 40 south Sudanese soldiers and civilians were killed when tribal fighters ambushed boats carrying U.N. food aid, the latest in a string of ethnic attacks threatening a fragile peace deal, officials said on Sunday.
Members of the Jikany Nuer group opened fire on 27 boats loaded with emergency rations destined for an area controlled by the rival Lou Nuer tribe on Friday, the U.N. World Food Programme said.
Hundreds have been killed and more than 135,000 displaced in south Sudan in 2009 in a surge of tribal killings rooted in long-standing feuds over cattle but aggravated by political discontent and weapons left over from two decades of civil war.
One U.N. source said Friday’s attack was thought to be the first time south Sudanese soldiers had suffered significant casualties in the tribal clashes.
“The environment is extremely volatile. There are signs the Lou Nuer may be gearing up for retaliatory attacks,” said the source, speaking on condition of anonymity.
The minister of information for Upper Nile State Thon Mom said Friday’s attack killed at least 40 people including troops from the south’s Sudan People’s Liberation Army (SPLA) escorting the convoy south on the river Sobat to the town of Akobo.
“Women and children who were on the boats were also killed, either directly by bullets or by drowning after jumping into the river,” said SPLA spokesman Malaak Ayuen Ajok.
He said the Jikany Nuer fighters had demanded to search some of the barges, south of the settlement of Nasir, suspecting they were carrying arms and ammunition to their Lou Nuer enemy.
They searched one, finding only sorghum and other rations, but opened fire when the rest of the convoy continued on its journey, he added.
Both Ajok and Mom said they were awaiting detailed information on the attack. “It could be less than 40 killed. It could be more. We should find out later today,” said Ajok.
INNOCENT SUFFER
The United Nations said there were fears for the fate of thousands of displaced people in and around Akobo now left without food aid after the attack.
“There are people who are desperately in need of food,” said the WFP’s programme director in south Sudan Michelle Iseminger. “As always, it is the elderly, the women and the children who are most in need.”
The WFP flew in an emergency delivery of 10 metric tonnes of food aid on Saturday, she added, short of the 735 metric tonnes that were either destroyed or looted from the boats.
“This year there have been roughly 135,000 people displaced by the violence. This time last year it was about half that number, and the year before even less,” Iseminger said.
“Things are definitely getting worse and it is mostly the innocent who are suffering.”
Heavy rains in Sudan’s semi-autonomous south have wiped out roads and left the Sobat river, a tributary of the White Nile, the only viable route for large deliveries of food aid.
Analysts say the rise in tribal violence threatens the fragile peace in the region achieved after a 2005 accord ended more than two decades of north-south civil war.
The 2005 Comprehensive Peace Agreement promised national elections, due in February 2010, and a referendum on southern secession in 2011. But many in the south are frustrated by the continuing lack of development and stagnation in the region’s oil-fuelled economy. (Editing by Janet Lawrence)