KHARTOUM, Aug. 11 (Xinhua) -- South Sudan government on Wednesday said 23 people were killed in an ambush by unidentified gunmen at the end of last week in the oil-rich Unity State in south Sudan.
"Unidentified men ambushed a truck at Bao area near Bantio, capital of Unity State, which resulted in killing of 23 people including south Sudan police officers", south Sudan government's Internal Affairs Minister, Gier Chuang told Xinhua.
"We have not identified the attackers yet, but we think they belong to Galwak Gai, a former Colonel who defected from the Sudan People's Liberation Movement (SPLM) due to differences over the recent elections held in April 2010", the minister added.
Unity State is one of the areas of tension between north and south Sudan as it lies on the border between them besides that it is one of south Sudan's oil-rich states.
South Sudan has been suffering from security tensions that claimed the lives of thousands of civilians because of tribal clashes, the phenomenon of cattle looting and disputes over pastures.
Observers express concern that the security situation in the south would deteriorate before the referendum on self- determination for southern Sudan, slated for Jan. 2011.
The south Sudan referendum has been stipulated by the Comprehensive Peace Agreement (CPA), inked between north and south Sudan in 2005, which ended a two-decade civil war between the two sides.