JUBA (Reuters) - South Sudan Wednesday accused Khartoum of backing a cross-border attack by insurgents that left over 72 people dead last week, the most violent incident of its kind since the South gained independence in August.
A force of around 800 fighters killed 15 soldiers and wounded 31 in clashes in Upper Nile state, according to the South Sudan army. They said that 57 members of the raiding force were killed in the incident.
"We strongly condemn this aggression from the Republic of Sudan," Philip Aguer, Sudan People's Liberation Army spokesman, said. "This is the biggest attack since the declaration of independence of South Sudan in that region."
No comment on the accusation was immediately available from the Khartoum government.
The SPLA spokesman said the raiding group was a mixture of Arabs and militia units from South Sudan under the command of renegade Generals Gordon Kong and George Athor.
The group crossed from Sudan in South Sudan's Upper Nile state on August 19, attacking a platoon of SPLA troops at Alan and later Kaka Moro. On August 20 they attacked Kaka el Pejaria, before being forced back across the border, Aguer said.
Athor was an influential commander in the southern army and a veteran of the south's long civil war with the north before he rebelled last year.
He was among a handful of prominent members of the Sudan People's Liberation Movement (SPLM) who felt overlooked when the party nominated candidates for last April's presidential and legislative elections.
South Sudan's ruling party said the attack was part of an ongoing strategy by Khartoum to intimidate Southern civilians and expose the South's new government as a failure.
"We thought this would finish as soon as the promulgation of South Sudan as a republic was realized. Very unfortunately this did not happen," Yan Matthew, SPLM spokesman, said.
"The (National Congress Party) continues to support the militias, or some of the elements of Southern Sudanese to rebel against their government," Matthew said, referring to the ruling party in Sudan.
From the beginning of the year up to the end of June, 2,368 people have been killed in 330 violent incidents across the South, according to U.N. data released in July.
(Editing by Sami Aboudi and Angus MacSwan)