By Hereward Holland
JUBA, May 13 (Reuters) - South Sudanese security forces have raided several aid agencies, a food warehouse and medical clinic in the east of the country where the army is fighting a rebellion, military and humanitarian officials said on Monday.
The United Nations said aid workers witnessed armed, uniformed men ransacking private homes and compounds of foreign aid groups in the center of Pibor town in Jonglei state at the weekend.
The army said the damage was caused by officers who defected from a state wildlife force, and denied regular soldiers were behind the attack on French aid agency Medecins Sans Frontieres, Italy's INTERSOS and the U.N. World Food Programme.
"We have been told by some of our NGO colleagues that their compounds were completely looted, and that everything inside, even fixtures like solar panels, have been taken," acting U.N. humanitarian coordinator in South Sudan, Yasmin Haque, said in a statement.
South Sudan's army spokesman Philip Aguer said members of the wildlife force broke into aid compounds, located just a few hundred meters from the town's army barracks and a government office.
"The preliminary information is that wildlife (protection officers) decided to defect and when they left they broke into some compounds," Aguer said.
All the organisations had evacuated their staff on Friday when most residents fled due to nearby fighting between the army and rebels, aid workers said, leaving the facilities empty.
South Sudan's government has struggled to turn its army, a loose group of former guerillas formed during decades of civil war with Khartoum, into a professional force since seceding from Sudan in 2011 under a peace deal in 2005.
Western diplomats say the government has been struggling to pay soldiers in recent weeks due to a budget crisis. South Sudan lost 98 percent of state revenues when it shut down its oil output in January 2012 in a row with Sudan over oil fees.
The African neighbours agreed in March to defuse tensions and resume oil exports from the landlocked South through the north but it will take until at least June for Juba to get fresh oil revenues.
A cycle of tribal violence has killed over 1,600 people in Jonglei since South Sudan's secession, uprooting tens of thousands of civilians and hampering plans to explore for oil. (Editing by Ulf Laessing and Alison Williams)