Nairobi/Juba  - The United Nations on Tuesday said it was concerned at the deterioration of security in Southern Sudan after the latest in a series of ethnic clashes claimed the lives of over 100 people.

Armed Lou Nuer tribesmen on Sunday attacked civilians and the military in the village of Duk Padiet in Jonglei State. More then 1,000 people have died this year in ethnic violence between the Lou Nuer, Dinka Bor and Murle tribes.

"UNMIS (the UN peackeeping mission in Sudan) is quite concerned about this latest attack," Kouider Zerrouk, deputy spokesperson for UNMIS, told the German Press Agency dpa. "The presence of a large quantity of weapons and the tensions between tribes constitute a serious factor for further deterioration of the security situation."

Tribal disputes, mainly over cattle, have long been common in autonomous Southern Sudan. Easy access to weapons left over from the civil war between the Muslim north and Christian and animist south has helped ramp up the body count.

A shift in the nature of the violence this year - which usually claim the lives of men guarding their cattle - has seen more women and children killed.

However, some witnesses say the latest attack was aimed at the security forces.

"It seems that the focus of the attack was on the organized forces, however we can't confirm the accuracy of this information," Zerrouk said.

Many in Southern Sudan believe that Khartoum is orchestrating the violence in order to undermine Southern Sudan's progression toward full independence.

A fragile peace has held between north and south since the end of a 21-year civil war in 2005.

The peace deal that ended the war laid out a road map that included elections in Southern Sudan, to be held next year, and a referendum on independence in 2011.

Southern Sudan's ruling party and Sudanese President Omar al- Bashir's National Congress Party are expected to contest the elections.

However, the UN is warning that if the violence continues, it will be difficult to organize the crucial ballot in the south.  dpa